# Recipe for a 67’ 400 hp build?



## Dukes67 (Jun 19, 2018)

Hello all,
I’m having problems sifting through the thousands of posts here and elsewhere on the interweb. Can anybody steer me in the right direction here to build a 400 h.p.ish, pump gas 400? 
I’ve got a 67’ GTO w/numbers matching engine I’m parking under my shop bench to preserve. To replace it I’ve found a 67’ Grand Prix 400, 350 h.p. and 670 heads. I hope to pick the engine up this weekend, break it down and make the salvageability/machining assessment by next week. If everything is reusable (and with hoping to keep the 670 heads for year correctness ) is 400 hp a reality on pump gas without having to go the stroker route? If so what recipe will get it done? Cam, pistons, head work, quench, etc.? 
I have seen some great posts from Bear, Pontiac Jim and others on different engine combinations, but I haven’t been able to find much on this one (or maybe I missed it?)
Any help is much appreciated!


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## bigD (Jul 21, 2016)

400hp is no problem at all with a 9:1 CR stroker. 

Not too hard to make 400hp with a high CR 400. But you'll need to mix in racing gas or octane booster. 

But, when you back the CR off to 9.5 or less, it becomes a bit more difficult. 

A Voodoo cam can make up for much of the CR loss. They are said to increase cyl pressure, by closing the intake valves sooner. I'm sure Paul Carter has built lots of pump gas 400's that made 400hp & more. He loves the Voodoo cams.

For an extra $1000-$1500, you can have a hyd roller cam set-up. The correct HR will make more power than most HFT cams. 

With the 670 heads, dish pistons will be needed, to get the CR down to 9.5. But, most every time I say that on a Pontiac forum, some guy will come on & say how he has been running over 10:1 CR with pump gas, for years, with absolutely no problems at all. Some also say you don't need hardened valve seats, in the early heads. Others say they're a good idea for the exhaust valve seats, for use with unleaded gas. 

I'd rather err on the safe side. No reason to take a chance IMO.

Icon IC891-030 pistons have a 14cc dish. 

https://www.cnc-motorsports.com/icon-ic891-030-forged-dish-pistons-4150-bore.html

I'd recommend RPM H-beam rods. They're $400 shipped. You can actually get by with good quality properly resized cast rods, using ARP bolts. But forged rods are better. 

SAE 4340 STEEL H-BEAM

Butler sells some of the new Eagle 5140 forged rods for $349 + shipping. But they are heavier & not as strong as H-beams.

https://butlerperformance.com/i-316...25-2-250-pontiac-rj.html?ref=category:1234812

Best to go with one-piece stainless valves, such as the Ferrea 5000 series. A good head job also includes bronze valve guides, good seals, 7/16 studs, etc. Best to have 'em done by somebody who has lots of experience doing performance Pontiac heads. Porting is not needed, for 400hp. A gasket match on the ports is a good idea tho. But, there have been plenty of 400hp Pontiac engines with completely original untouched ports.

You mentioned quench. Most agree that .040 or slightly less is a good quench distance. 

A good correctly built & tuned Q-jet, & a stock iron intake are plenty good to 400hp & well beyond. 

I'm sure some of these other guys can give you more details than this. 

Good luck with it !


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## Dukes67 (Jun 19, 2018)

Thanks for the reply bigD!
I really appreciate the recommendations.
I plan on having the parts and pieces down to the machine shop next week barring any major findings in the tear down. If everything is a go I’m planning on the following beside the normal clean and inspection.

1.Line bore, block the deck. I’ll shoot for that recommended quench.

2.Hone to 30 over for ease of finding new pistons. Dished pistons for decreased C/R. I will go with the upgraded rods ARP bolts throughout. (thanks for the rod recommendation!) Balance connecting rods and pistons. Do you have any ring recommendations?

3.Heads reconditioned w/hardened seats, SS valves, upgraded bronze guides/springs. You don’t recommend porting the heads? 

4.Polish/balance/chamfer the crank (hopefully it won’t need too much, it’s from a low mileage family car). Do you have any bearing preferences throughout the engine ?

5. I’ll check into the Voodoo cam, thanks for that! If I go with a roller setup is there any concerns on this engine with bracing? (Sorry I’m still learning on these Pontiac’s)

6. Rear seal (a small but big deal) I’m planning on the rope style seal from Best Gasket. Pros/Cons vs. Vitron?

7. I was told there is a hidden oil galley plug on the rear of the engine that not only “must be there” but was recommended to drill and tap it for better cam oiling. Good or Bad idea?

8. Is an upgraded oil pump available /required for this build?

9. Recommendations for timing chains?

10. I’d like to keep the original intake manifold, Q-jet w/forward fuel line and ignition for originality.

I really appreciate all the insight here. We don’t have (or I haven’t found) much of a Pontiac following here in Salt Lake. So I don’t have many people to bounce ideas off of. I’ve found what I feel is a very capable machine shop (tooling wise), but unfortunately this and other shops I’ve talked to local seem to have limited Pontiac experience.


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## Colorado67GTO (Sep 11, 2014)

Dukes67 said:


> Thanks for the reply bigD!
> I really appreciate the recommendations.
> I plan on having the parts and pieces down to the machine shop next week barring any major findings in the tear down. If everything is a go I’m planning on the following beside the normal clean and inspection.
> 
> ...


I am by no means an expert and there are a lot of other people on this forum that have much more experience than me on Pontiac engines. That said, I went through exactly the same process you are going through on my 67, so I already found many of the answers.

The main thing you should ask yourself is how fast you plan to spin the engine when you are done. An 8 grand engine will take significantly more work and parts than a 5 grand RPM engine.

One caveat to all my comments. I have built and run my engine, but haven’t driven it yet, so take all this with a grain of salt.

1. I would not block the deck unless it is warped. It will change all the stock measurements. Only do if needed. 

2. The rings I used came with the ICON pistons. They were 4032 Alloy. 

3. If you are looking at an 8 grand RPM engine, then maybe. A lot of people screw up their heads getting them ported by people that don’t know what they are doing. It sounds like what you are describing, you probably don’t need porting. 

4. I used Clevite for all bearings. They are a very good brand and I don’t think you can go wrong. 

5. Bracing more depends on how fast you spin it and how hard you will be driving it. Just on street, it probably is not necessary. Strip or high RPM, you will need it.

6. I used Vitron one piece and haven’t had any leaks. Some people have reported bad results with Vitron and have gone back to rope. 

7. Yes, the hidden oil galley plug. Just remind your machinist and verify it is in when you get it back from machining. As far as drilling the oil supply hole, my understanding is that is not needed unless you go high RPMs. I would say if you don’t need it, don’t do it.

8. From my reading, the big mistake Pontiac builders make is getting a high pressure pump. Stick with 60 psi. In some applications, there is a need for higher volume, such as when you drill out the oil galley, but if no major changes, stock 60 psi should be fine. 

9. I just went with a comp double sprocket chain drive. That should be fine for any basically stock build. I have seen some say to stay away from the double sprocket, but I think that was because of non-stock covers and clearance issues. 

10. The Qjets are what the engine and manifolds were designed around, so you should be good. Remember, the more you change from stock, the more potential problems you will run into.


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## bigD (Jul 21, 2016)

1. You may not need a line bore. May just need a light line hone. May not need either. A good machine shop can check it for you. 

The decks need to be squared up with the crank centerline. But, you may not need any extra cut off the decks. The less cut off, the better. It depends on the exact stroke of the crank, exact rod length, and exact piston pin height(compression distance). You can buy custom pistons with any pin height you want. This will allow you to get zero deck height, without cutting extra material off the decks. Auto Tec pistons are the cheapest customs I've found. Shannons Engineering is the cheapest Auto Tec dealer I've found. He must be a volume dealer. A guy at Auto Tec recommended him to me. There are also some Pontiac shops who can order 'em. 

https://shanonsengineering.com/coll...ll-block-pontiac-400-428-455-flat-top-pistons 

2. Don't have the engine bored 'til you choose a piston. Have the machine shop tell you what is the smallest bore size that your block will clean up. Then chose a piston in the smallest bore size that will work, based on the numbers the machine shop gives you. With custom pistons you can usually get them in most any size, in .005 increments. The cheapest Auto Tec customs are made from what they call shelf blanks. They usually stock these in most of the popular sizes, then machine them for whatever engine & specs needed. But, if they don't have a shelf blank in the exact size you need, they can make a new set from scratch. They'll just cost more. 

As for rings, I always just used pre-fit TRW moly rings. But, many today recommend file-fit rings, so that the engine builder can file 'em for an exact ring gap. Of course, this is extra cost labor. Total Seal brand rings are popular. DON"T buy gapless rings. The most common ring size is 1/16" top & 2nd rings with 3/16" oil rings. 

3. Porting not needed. Probably not worth the expense, for most street guys. 

4. I always just used common TRW bearings, without any problems. But, some swear by certain brands & particular types. I'd ask some Pontiac engine builders for their opinion. 

5. Voodoo - Hydraulic Flat Tappet - Lunati Power

Voodoo - Hydraulic Roller - Lunati Power

Don't need lifter bore braces with small HR cams. But won't hurt anything either. 

6. Most reviews of the one piece seal have been good. But, as said, some prefer the Best Gasket rope.

7. I ran with a hole in that plug, and at least 70psi oil pressure, in my 455 bracket engines. Never had a problem. But, as mentioned, some prefer the 60psi pressure of the M54DS oil pump. I added some shims under the pressure spring, too increase pressure. Some say the larger 3.25" mains of the 455 block need a little more pressure than the smaller 3" main blocks. Opinions differ. Some say it all depends on the bearing clearances.

8. The M54DS is the most popular pump. Some say you should take 'em apart & clean 'em up real good. Butler sells a pump which they have modified, and has a thick bottom plate. You can buy a thick bottom plate from them & other sources. Some have reported leaks with the thin stock plates. Some put 2 stock plates on 'em. 

https://butlerperformance.com/i-244...creen-bpi-m54ds-pro.html?ref=category:1234738

http://nitemareperformance.com/high_vol_std_pressure oilpump.html

http://nitemareperformance.com/pro_oilpumpplate.html

9. Well known Pontiac racer, engine builder, & Q-jet expert, Cliff Ruggles, uses & recommends the Melling stock replacement timing set. The chains are plenty strong. And any chain, including the high dollar true roller chains will stretch almost as soon as the engine is broke in. After discovering this, many years ago, I switched to the TRW replacement set. No problems ever. 

https://www.rockauto.com/en/parts/melling,3350S,timing+set,5756

The Cloyes brand replacement set is a #C3007k . They're about $25, from an Amazon seller.

https://www.amazon.com/Cloyes-C3007K-Timing-Sets-K-Sets/dp/B000C0AJKY

10. It's a good idea to permanently plug the exhaust heat riser holes in the '67 intake. Otherwise you MUST run a stainless steel separator plate, & the correct gasket set-up. Pontiac had lots of problems with this set-up & discontinued it after only 1 year. Much easier to just block 'em off & run the later type gaskets. 

Nothin wrong with the stock type points ignition system. I ran it in all my drag cars back in the 20th century. But, if you want later technology, while keeping the factory look, you can get the Pertronix points conversion set-up.

https://www.summitracing.com/parts/pnx-71181


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## Dukes67 (Jun 19, 2018)

Once again thanks for all the insight you guys! This really helps for coming up with a good game plan for the build.
As far as performance requirements the car won’t be getting driven very hard. This is a replacement I bought for my father. He unfortunately sold his original 67’ when he joined the Marines in 69’. Sadly his was destroyed shortly after selling it. He’s seventy now and drives more like a grandma, but still gets a kick out of driving the old car. So I’m more concerned about the reliability/originality look of the engine than an all out fire breather (there is a chance I may be getting two of these engines in the deal, if that’s the case the second one will be). But I would still like to get after it slightly if I steal it for a spin. 

Thanks again for all the tips!


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## Dukes67 (Jun 19, 2018)

“Colorado 67” thanks for the reply. I get out to Golden a few times a year. I hope to see your car out on the road!


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## Dukes67 (Jun 19, 2018)

Thanks for all the detail and links bigD. Talked to Lunati today. Planning on the roller setup. Seem like great guys there!


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## 1968gto421 (Mar 28, 2014)

This is an interesting link on 400hp from a Poncho 400:

400 hp out of 73 pontiac 400

Also this from an excellent Pontiac builder:

408 build for a 69 Judge! Dynoed tonight. - PY Online Forums

With the problems you encounter with the '67 intake, you might check the parts for sale here and on the PY forum for a '68-'72 Pontiac iron intake. I've had good success with the Edelbrock Performer RPM (the std Performer intake is not so good, less power than with the Pontiac stock intake due to tiny passages).

(FYI-bigD has doing and racing Pontiac engines for over 45 years, I respect his advice.)


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## bigD (Jul 21, 2016)

Dukes67 said:


> Thanks for all the detail and links bigD. Talked to Lunati today. Planning on the roller setup. Seem like great guys there!


It has been said by many that most all Pontiac HR lifters are actually Chevy lifters, with Pontiac link bars. Chevy lifters have a lower oil band. Paul Carter uses Hylift Johnson lifters & grinds an oil groove, from the lifter bore oil feed hole, down 1/4", in order to connect with the lower oil band of the Chevy lifters. 

I've read that the only HR lifters made, which have the higher Pontiac oil band, are the Comp Cams 857-16 lifters. These are made for CC by Shaver. It has been posted that when CC is out of the Shaver made lifters, they substitute lifters which are made by Morel. These are said to have a part number of 857M-16. They are the Chevy type lifters. 

PY Online Forums - View Single Post - 857M-16 Lifters

PY Online Forums - View Single Post - 857M-16 Lifters

None of the cam companies make their own lifters. 

So, If you want Pontiac lifters, I'd buy CC 857-16, made by Shaver. Or, buy some other brand & pay the machine shop to grind the oil feed grooves. 

http://forums.maxperformanceinc.com/forums/showpost.php?p=5865106&postcount=28

https://www.amazon.com/Competition-Cams-857-16-Retro-Fit-Oldsmobile/dp/B0014F6F36

Just a word about that high hp Paul Carter build. It had SD Performance ported heads, a ported intake, Hylift Johnson roller lifters, and a complete Paul Carter build. I figure that engine would cost well over $10k, & probably over $12k, for the complete engine & dyno time. So, when planning an engine build, you need to keep this in mind, unless you have an unlimited budget.


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## PontiacJim (Dec 29, 2012)

All good suggestions from everyone and seems you have read a few older postings. Things I would suggest:

I like the 3/4 groove main bearings for a little better oiling.

If you can handle the price, I would get the Butler 60PSI pro oil pump which is improved/blueprinted and tested for flow. I added this to my build, but the Mellings 60 PSI pump is fine if your budget is tight. 

I like and purchased the Nightmare machined oil pump shaft. It may require a little fit/clearance, but it is a heavy duty piece. If anything, get an aftermarket hardened shaft at a minimum and they are inexpensive. Standard sleeved & hardened oil pump driveshaft

Deburr the inside of the block at the valley pan/lifters. You will see a lot of jagged edges from the casting. Smooth this all up. Jagged edges can be stress areas and could lead to a crack or if you have a large enough chunk of casting, it could break off which you don't want going into your engine. Never had a problem in not doing this, but if you can, I would grind it smooth. I did do this on my present engine build.

Replace the oil galley cup plugs with threaded plugs to make them more secure. Make sure they do not get inserted to deep and close off any of the oil supply.

You mentioned you did not want to go stroker on the engine, but when you add up separately what it will cost for pistons, rods, bearings, balancing, etc., you may find it a reasonable deal - and you get a new crankshaft. Always build a Pontiac for torque. Bigger cubes will allow you to build the engine less "peaky" than a 400 where it will need higher RPM's. Lot easier to hit your goal of 400HP and lower compression with an additional 67 cubes, but again, it is more about torque.

3-angle valve job.

Get a new harmonic balancer.

Mini starter so you can clock the starter solenoid away from the heat of the exhaust manifold.

Ram Air cast iron exhaust manifolds over headers unless you absolutely gotta have headers. A Pontiac wants to breathe.

A good distributor curve - whether using points or electronic.


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## bigD (Jul 21, 2016)

"...Get a new harmonic balancer..."


There are lots of high dollar balancers for Pontiac. But, unless you insist on having one with all the timing marks on it, the stock replacement Powerbond 1056N, will work just fine. They're about $45 shipped from Amazon sellers. 

https://www.amazon.com/Dayco-PB1056N-Harmonic-Balancer-POWERBOND/dp/B013YN6R38


"...Mini starter so you can clock the starter solenoid away from the heat of the exhaust manifold..."

I've used a couple of the Summit mini starters on my 455 bracket engines. Works great, even when the engine is hot. Eliminated all my hot start problems. But, if you wanna spend more, there are several higher priced brands.

https://www.summitracing.com/parts/sum-820311/overview/make/pontiac

I also use a Ford type starter solenoid, mounted on the firewall. Had a cheap black plastic one that stuck in the ON position. So, I now use the Cole Hersee 24037.

https://www.amazon.com/Cole-Hersee-...sr=1-10&keywords=cole+hersee+starter+solenoid 

Lots of racers use the QuickCar version.

https://www.amazon.com/QuickCar-Racing-Products-50-430-Solenoid/dp/B003TTYSH0


"...Ram Air cast iron exhaust manifolds..."

Some say these RARE manifolds are the best. These have the larger 2 1/2" outlet. 

https://www.ramairrestoration.com/rm-1-os-d-port-ram-air-style-factory-headers-oversized.html


"...A good distributor curve..."

Some think the mechanical advance needs to begin increasing the timing from about 1000 rpm or slightly higher, and achieve max advance by 3000 rpm. In order to accomplish this, the advance weights need to be clean and adequately lubricated so that they will move smoothly & completely. 

The rate of advance is then regulated by the advance weight springs. Lighter springs will allow the weights to advance timing sooner. There are kits which have lighter than stock springs. Most do not recommend using the lightest springs in the kit, because they don't seem to last very long. You may be able to get your desired curve by using one stock spring & one weaker spring. Will just have to try different spring combos to see what works for you.

You may need to add a positive advance stop to your dist. For example: if you want to have 15° initial advance at idle and 35° total advance, but your dist will advance 24°, if you set your initial at 15° you'll end up with 39° total -- 15° + 24° = 39°. In that case, you'd need to make a stop that would limit the amount of mechanical advance by 4°. There are several ways to achieve a positive stop. 

Most street guys like to also use a vacuum advance, for street cruising rpm. Some stock vac advance units add too much advance. But, there are adjustable vac advance units which will allow you to add only the amount of vac advance you want. There is a Crane brand kit which has the adjustable vac advance and 3 pairs of advance weight springs.

https://www.amazon.com/Crane-Cams-99601-1-Adjustable-Advance/dp/B000CIO2KY

On many parts, you can save a few bucks if you buy from Summit, with an order of $99 or more. But, for smaller orders, Ebay or Amazon usually has the best shipped price. If price is not an issue, just ignore this statement. 

There is a LOT of online info on setting your ignition curve.

https://www.google.com/search?q=how...9i57j69i64.20712j0j4&sourceid=chrome&ie=UTF-8

Or, you can send your dist to guys who will completely rebuild it & set the curve for you. Some of these guys are not cheap, at all. But, if your dist has some severe problems & you wanna use it, that may be an alternative to buying another dist.

Here's one of the high dollar rebuilders. He posts on the PY forum.

http://forums.maxperformanceinc.com/forums/member.php?u=143447


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## Dukes67 (Jun 19, 2018)

Thanks you guys, it’s a wealth of information. I really appreciate the response!

I was planning on buying the upgraded oil pump as long as you guys have had good success with them (sometimes it’s worse off going aftermarket). 

The exhaust. I was trying to stick with the original for correctness but if I need to ditch the originals for lack of flow so be it.

Good call on the balancer! I was just reading a horror story of a reused one that wiped out a new rebuild.

Jim, the cup plugs your talking about are those the ones at the front of the block? Thanks for the heads up about the deburring. This wasn’t brought up with the machinist.

If I go the stroker route which one do you guys prefer? I’ve read some bad reviews about the Eagles having some bad machining? Maybe Scat as an alternative?

Price is always a concern but I’m more than willing to build it right. This has been a drop in the bucket compared to owning an airplane, and has been every bit as enjoyable.


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## bigD (Jul 21, 2016)

"...If I go the stroker route which one do you guys prefer? I’ve read some bad reviews about the Eagles having some bad machining? Maybe Scat as an alternative?..."

The only problems I've read about are with the Eagle CAST cranks. I'd go with a Forged crank. But if you prefer Scat, Butler only charges about $50 more. 

The Butler 4.25" stroke assemblies are very popular. Lots of options.

https://butlerperformance.com/i-316...-400-block-4-250str.html?ref=category:1459542

Most say that there is not a big power difference in the 4.25" stroke and the 4.21" stroke. The 4.21" stroke assemblies have stock Pontiac length rods, and Pontiac size rod journals. The 4.25" assemblies have BBC size rod journals, and longer rods.

https://butlerperformance.com/i-244...400-block-4-210-str.html?ref=category:1459542

WARNING ! If you build a stroker, it will have about 500 or more torque, at about 3000-3500 rpm. This kind of torque can easily break drive line parts at WOT, IF your rear tires get good traction. My home built 455's broke several auto trannies & a couple of 10-bolt rear ends. Big torque is fun, but can be destructive.

Some choose to go with a 4" stroke. This would produce slightly less torque, in a similar build. You'd also need less dish in your pistons. 

https://butlerperformance.com/i-245...-400-block-4-000str.html?ref=category:1459542

If you decide you'd rather not trust your area shops with your shortblock build, you can buy a crate shortblock from OK, & have it shipped. Here's a link to a basic build. You can add to this a forged crank, in the stroke you choose, & dish pistons, as extra cost options. Len will furnish the block. Or, you could send him yours. I've read some good reviews of Len, from some of his customers. 

http://lenwilliamsautomachine.com/455_Short_Block.html


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## PontiacJim (Dec 29, 2012)

The oil galley plugs are up front on each side of the cam tunnel. 1st picture shows you where they are located. 2nd pic shows from a side view the pipe plug. The hole is tapped and pipe plug installed. You don't want too deep, but deep enough, and make sure no interference with the cam sprocket. 3rd pic shows the "hidden" rear oil galley plug as seen looking down the distributor hole. Just want to make sure it is not forgotten during re-assembly. *See pics in next reply as they did not upload.
*
With regards to the crank, early on there were issues with the aftermarket cranks - made in China and the quality was a little sketchy. From my reading, this was improved and corrected and there have not been any issues in years.

You can go forged crank as bigD points out, but it is not really necessary for street unless you were to really spin higher RPM's with a stroker engine which would also mean much better flowing heads to take advantage of the higher RPM's.

Looking at the Butler website, they offer the cast & forged crankshaft in 4.00" stroke and 4.25" stroke. The 4.00" stroke (same as the 421CI) with .030" over pistons gives you a 433CI. The 4.25" stroke gives you right at 460CI.

The forged crank offering bigD points out does come in a 4.21" stroke and with a .030" overbore would give you 455CI using the stock Pontiac length 6.625" connecting rods.

My opinion here. I would go with the Eagle 4.25" cast crank with 2.20" Chevy rod journals. Why? Cast will be fine for the RPM range the engine will see. So let's add it all up if you were to purchase parts individually.

Eagle cast 4.25" stroker crank. Cost $290 @ Summit. I like the Eagle SIR I-beam Big Block 6.8" length forged rods. Cost $329 @ Summit. I cited Summit because shipping is listed as free over $100, even on the crank according to their website. So total so far is $611 for crank & rods.

Pistons will need to be custom and that means forged and will be pricey - as most all forged pistons are not inexpensive. Butler offers Ross custom pistons with pins/rings for the above application for $699. You will need dished pistons to match your head chamber cc's to try and get down near 9.0-9.3 compression. Total is now $1,310. 

Bearings are $70 for 3/4 grooved mains & $57 for rods. Total now is $1437. 

Balancing will run you about $250. Total now is $1687.

A complete 4.25" Eagle stroker rotating assembly, balanced, from Butler is $1598. Not only is the price lower, you know all the parts will work together. The shipping costs will add a few more dollars and may cause it to be slightly higher than piecing the assembly together.

The added stoke is also your power adder though the additional cubic inches and longer stroke torque. Keeping the 400 stock and do some upgrading in a few areas like SIR forged I-beam rods, forged dished pistons, and balancing and the assembly will be much cheaper, but then you will need to pull more HP/TQ from a bigger cam which will most likely mean running the engine to a higher RPM range - which is still doable and may sacrifice low end power. For a street engine, you want the power/torque in the lower-to upper mid range RPM's; stop light to stop light acceleration. A hot cam in a 400CI will be milder in a bigger inch engine so you will still have good power, but a better mannered engine.

Here is a real life comparison. A car magazine tested side-by-side a 1970 Ram Air IV GTO and 455 GTO with Ram Air and AC. 

The RAIV had close ratio 4-speed, 3.90 gears. Factory advertised 10.5 compression, 366HP @ 5100 RPM, 445 TQ @ 3600 RPM. Test weight 4230 pounds.

The 455 had a TH-400, 3.55 gears. Factory advertised 10.25 compression, 360 HP @ 4300 RPM, 500 TQ @ 2700 RPM. Test weight 4455 pounds.

Performance numbers went like this:

RA IV 1/4 mile 14.60 @ 99.55 MPH shifting @ 6100 RPM's
455 1/4 mile 14.76 @ 95.94 MPH shifting @ 5400 RPM's

RA IV 0-60 6.0 seconds
455 0-60 6.6 seconds

Passing speeds
RA IV 30-70 MPH 5.0 seconds
455 30-70 MPH 5.3 seconds

Gas mileage
RAIV 8.9 MPG
455 11.8 MPG

My guess is that if the AC were dropped that the 455 would have been about equal in performance. I did use the Wallace 1/4 mile calculator and then used the lighter weight of the RAIV car to get a faster 1/4 mile time of 14.51 seconds showing the 455 would have beat the RAIV car! Better street manners & better gas mileage at higher TQ and much lower RPM's.

Again, my opinion, and always best to put together a plan with your machinist or engine builder. :thumbsup:


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## PontiacJim (Dec 29, 2012)

Pics did not take above of the oil galley plugs, so here they are.


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## bigD (Jul 21, 2016)

"...Looking at the Butler website, they offer the cast & forged crankshaft in 4.00" stroke..."


The way I read it, the 4" stroke crank is forged only. I think the only cast crank is a 4.25 stroke. 

" New Forged Crank 4.000" Stroke " 

https://butlerperformance.com/i-245...-400-block-4-000str.html?ref=category:1459542

Here's an Eagle crank thread from PY. 

http://forums.maxperformanceinc.com/forums/showthread.php?t=708028


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## PontiacJim (Dec 29, 2012)

bigD said:


> "...Looking at the Butler website, they offer the cast & forged crankshaft in 4.00" stroke..."
> 
> 
> The way I read it, the 4" stroke crank is forged only. I think the only cast crank is a 4.25 stroke.
> ...



Yes, I believe you are correct. I looked at just the crankshaft as an individual piece and Butler does list a 4.0" cast crankshaft for $339. (Description: New Pontiac Cast Crankshaft 3.00" Main Journal Size 4.000" Stroke 2.200" BBC Rod Journal 6.700" Rod Length), and also looked at the rotating assembly which had the forged crank.

However, I missed the "Not Available" just above the price as I looked at it quickly. So the only offering in the 4.0" stoke crank at this time seems to be the forged piece as part of the rotating assembly they have. No idea why they have it listed if it is not available or has been discontinued.


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## Dukes67 (Jun 19, 2018)

Once again thanks for all the info and detail!

I probably should have mentioned this earlier but the car has the 4 speed Muncie, an 8.2 BOP that I just put a posi in and swapped out the 3.55 for a 3.36 for a little better highway performance. The trans will be getting a full rebuild while the engines out and a balance on the driveshaft. Is there any reason to go to a chrome alloy style U-joint? I’ve always used the cheaper ones hoping they would be more like an electrical fuse. Breaking before something more costly breaks.

The block- I did look around at just purchasing a new built engine or block, but would like to build it local so I can make sure all of the little improvements you guys mentioned can be added. That’s why your advice here is priceless. You have done the personal leg work. I wish they would start a separate index just for you guys to list your proven builds. Thanks for the shots of the block plugs-that is on the to do list!

A question about the roller setup. If I go the total roller cam/rockers can I than drop the Zinc oil and run a standard synthetic?

Intake- once again I’m trying to keep this as close to original looking as possible. “68’ GTO” mentioned about changing this out for a later model. I happen to have one of these around the garage and there’s a significant difference in appearance. Is this imperative to upgrade? 

The Heads- I did look into the SD’s they look like they have a way to really open the 670’s up but at the same time is this really necessary for a street/400 hp build? Or just the plan of a good refresh and roller setup be good enough?

Crank-The more you guys talk about the stroker setup the better that’s sounding. Have any of you bought the pre-balanced setup? We’re they set up/balanced properly from the factory? 
The link about the Eagle failures is similar (and tragic for those owners) to what I had read elsewhere. But about the same vintage of posting(about 7yrs ago). I would hope by now if there was an issue it has been addressed by now. 

Thank you also for the distributor info..

Hope to pick the engine up tomorrow and start the tear down. Weather permitting, it’s snowing like crazy here in Utah!


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## bigD (Jul 21, 2016)

"...If I go the total roller cam/rockers can I than drop the Zinc oil and run a standard synthetic?..."

Yes.

"...Intake- once again I’m trying to keep this as close to original looking as possible. “68’ GTO” mentioned about changing this out for a later model. I happen to have one of these around the garage and there’s a significant difference in appearance. Is this imperative to upgrade? 

The '68-'72 intakes were very similar to the '67. They just didn't have the exhaust heat holes & the "smiley face" "hot slot" under the carb. But, I'd use the '67 intake before I'd use a '73-'79 version. The later intakes will bolt up & work, but they all have EGR holes on the pass side that must be plugged. And, the '73-'74 models had a huge sump underneath, requiring a '73-'79 valley pan. It also makes 'em heavier. I'll try to post some intake pics. 

"...The Heads- I did look into the SD’s they look like they have a way to really open the 670’s up but at the same time is this really necessary for a street/400 hp build? Or just the plan of a good refresh and roller setup be good enough?..."

Porting, for the power level you want is not needed. Whether to go with stock stroke or stroker will have to be your call. 375hp is easy, with stock stroke & a HFT cam. 400 is easy with a 4" stroke & HFT cam. Over 400hp, plus near 500 torque is easy with a 4.21 or 4.25 stroke & HFT cam. Correct HR cam can easily increase hp 15-25hp, or maybe a little more, & still be very streetable. 

I'd consider the cam a major decision. Millions of Pontiac engines have lived long lives with hft cams. But, when the non-USA made hft lifters came along, there were lots of cam failures. Many blamed it on the oil, because of the reduced zinc levels. Anyhow, there are lots of Pontiac engines still being built with hft cams. You just need to use oil with the zinc additive, AND break the cam in correctly. This means running the rpm up to at least 2000, immediately after starting, & keeping it there for at least 20 minutes. DON"T LET IT IDLE. Best to vary the rpm, above 2000 & back down again, rather than leaving it steady. Some vary the procedure slightly. You can Google something like "how to break in a hydraulic flat tappet cam", and get lots of detailed explanations, & probably some YouTube videos. 

But, lots of guys nowadays are choosing the HR cam set-up. This can easily cost from $1000 to $1500 more than the hft cam set-up, or even more, depending on the lifters & rockers you choose. Advantages are: a little more power, and not having to worry about cam/lifter break-in or getting enuff zinc in the oil. I assume that the longest lasting rockers would be the Crower stainless steel units. But, they are also probably the highest priced. The scorpion Endurance series alum rockers might be a good choice. Lots of guys believe in the Harland Sharp brand rockers. Avoid PRW and any other cheap Chinese made rockers. There have been lots of failures reported. 

https://butlerperformance.com/i-244...-rollerized-1-5-rockers-set-cro-73627-16.html

https://www.summitracing.com/parts/scc-scp3052/overview/make/pontiac

https://www.jegs.com/i/Harland-Shar...R18ophtqJUC8LdITLSILMlr_Bjy_4XbAaAi3PEALw_wcB

"...Crank-The more you guys talk about the stroker setup the better that’s sounding. Have any of you bought the pre-balanced setup? We’re they set up/balanced properly from the factory?..."

I assume you're referring to those that were balanced by Eagle & NOT Butler. I'd pay the extra cost & go with a Butler assembly. But, I'm sure there are quite a few who have had good luck with the Eagle factory assembly. KRE can also supply you with a balanced stroker assembly. Their price list may not be current. They also still show a cast 4" stroke crank. Don't think those are still made. Have to add $200 to the listed price, for balancing. They come with KB Icon pistons. Can upgrade to Ross, for extra cost, but the Icon pistons are considered good quality. KRE is a well respected Pontiac engine builder. 

Kauffman Racing Equipment

There are quite a few Pontiac engine builders who can set you up with a balanced stroker assembly. Here are a few.

https://www.facebook.com/PaulKnippensMuscleMotors/?ref=br_rs

http://www.dcimotorsports.com/services/pontiac-v8-engine-builder/

http://www.sandovalperformance.com/rotating-assemblies


"...Eagle failures...I would hope by now if there was an issue it has been addressed by now..."

If you wanna take a chance on an Eagle cast crank, that's your decision to make.

Here are the pics I mentioned. As you can see, there's not much difference in the '68-'72 intakes.


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## Dukes67 (Jun 19, 2018)

Big D, Jim, thanks for the time thoughts and effort on the questions.

I got the donor engine to the house today ( no help with the soggy conditions here) and broke down. The engine was not able to turn over when I picked it up, but once it was all disassembled it was just a little bit of rust and moisture holding things up. Hopefully have it at the machine shop Monday!

The crank had a little moisture on it but no pitting. It’ll be a good crank if someone else needs one.

Barring any major findings during machining I think I’m going with the 4.25, pre-balanced stroker from Butler. Thanks for all the tips and I’ll post progress as it comes!


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Big D, Jim, thanks for the time thoughts and effort on the questions.
> 
> I got the donor engine to the house today ( no help with the soggy conditions here) and broke down. The engine was not able to turn over when I picked it up, but once it was all disassembled it was just a little bit of rust and moisture holding things up. Hopefully have it at the machine shop Monday!
> 
> ...


Looks good and it has the AFB intake, not the Q-jet intake.


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## bigD (Jul 21, 2016)

PontiacJim said:


> Looks good and it has the AFB intake, not the Q-jet intake.


Since you'll need another intake anyhow, I'd buy a '72 model. They'll work on both pre-72 & '72-up Pontiac heads. That way, if you should ever wanna switch to the popular 6X heads, the intake will work. Will also make the intake more sellable, should you ever wanna sell it. There's a guy in Alabama who usually has one for sale. Since they're heavy, the shipping ain't cheap. 

1972 Pontiac 4bbl Intake - PY Online Forums


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## Dukes67 (Jun 19, 2018)

Good eye on the AFB intake! Know anybody looking for one?

Engine parts are at the machine shop. Fingers crossed the block and heads check out. Any reviews on this intake manifold? I believe it’s for a 68’ 400 Q-Jet?
Jim, if you happen to read this you recommended a new harmonic balancer with a part number of 1056N. I went to purchase this and it doesn’t show it's applicable to a 67’, only 68 and up. Will this still work for this engine?


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## bigD (Jul 21, 2016)

I think all '68-up 4-barrel Pontiacs had a Q-jet intake. I could be wrong, but I think maybe '67 was the last year Pontiac used an AFB. I know I've read that the '67 326HO had one. 

https://www.hotrod.com/articles/hppp-1101-1967-pontiac-firebird/#hppp_1101_10-1967_pontiac_firebird


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## cij911 (Oct 25, 2017)

Any additional thoughts on 455 w/ aluminum heads vs. 460+ cu. in. ? I keep coming back to Len Williams' 455 option and adding aluminum heads for an additional $2500 ($8k for fully built motor) - Len believes the aluminum heads will add upwards of 50hp, so that is a nice amount of power. Or save the $2500 and have a decent 455 for $5500. Perspectives?


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## bigD (Jul 21, 2016)

Hey, it's your call. Besides making more power, you can run more compression safely, with the alum heads. Since they'll have more CR & more flow, I think it is possible to make 50hp more, with the right cam. 

BUT, you can make around 400hp/500 torque with 6X heads & 9:1 CR. That's more than enuff for most street cars. It'll run 12's in the 1/4 mile. The bracket engine I have now has 6x-8 heads with a Summit 2802 cam. It's a very conservative combo, but should still make near 400hp/500 torque.

If you go with an aftermarket crank, I'd spend the extra $400 or so & get a forged crank. There have been lots of failures of the cast Eagle cranks.


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## cij911 (Oct 25, 2017)

bigD said:


> Hey, it's your call. Besides making more power, you can run more compression safely, with the alum heads. Since they'll have more CR & more flow, I think it is possible to make 50hp more, with the right cam.
> 
> BUT, you can make around 400hp/500 torque with 6X heads & 9:1 CR. That's more than enuff for most street cars. It'll run 12's in the 1/4 mile. The bracket engine I have now has 6x-8 heads with a Summit 2802 cam. It's a very conservative combo, but should still make near 400hp/500 torque.
> 
> If you go with an aftermarket crank, I'd spend the extra $400 or so & get a forged crank. There have been lots of failures of the cast Eagle cranks.


Thanks!


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## Dukes67 (Jun 19, 2018)

Block came out good!! 30 over took care of a slight ridge. 670#’s checked out, getting new valves, screw in studs. Butler 4.25 stroker kit is 4 weeks back ordered to get the Ross 30cc pistons?. Lunati Voodoo cam kits on the way. Nightmare oil pump shaft showed up today. Maybe by spring we’ll have an engine!


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Good eye on the AFB intake! Know anybody looking for one?
> 
> Engine parts are at the machine shop. Fingers crossed the block and heads check out. Any reviews on this intake manifold? I believe it’s for a 68’ 400 Q-Jet?
> Jim, if you happen to read this you recommended a new harmonic balancer with a part number of 1056N. I went to purchase this and it doesn’t show it's applicable to a 67’, only 68 and up. Will this still work for this engine?


The '67 balancer is a 2-piece design. The '68 and up is one piece. You want to use the balancer that came with the engine as it matches the timing cover which is the 8-bolt style water pump.

https://butlerperformance.com/i-244...-dampers-59-67-pontiac-6-bolt-aac-630155.html

You will want to get a new set of these for the water pump: https://butlerperformance.com/i-244...less-set-aau-n140pf.html?ref=category:1287678

You want to make sure you have a good water pump design on the impeller. You want one that is a cast iron, not a stamped steel design. Butler has a FlowKooler pump which I have no experience with. Said to be better than factory. There are different types of impeller designs and I could not tell you which one is better over another. Rock Auto actually has some that are inexpensive and the photos show the cast iron impeller in 2 different designs. You could also have your original rebuilt. So I can't really give you any opinion on best choice - never had a problem with any that I was ever aware of, so whatever I installed at the time is what I used. 

Many will change out to the later 11-bolt timing cover/balancer/water pump & divider, because parts are more readily available. But, this is more$$. I would not do this unless the timing cover seal area was badly pitted or oxidized, or water passages badly eroded. I believe you would also have to swap out the power steering bracket/mount on the engine when going to the later set-up. 

The '68 Q-jet manifold is fine. It will work. You can go aluminum, but not much more power improvements. The advantage is weight savings which you probably won't notice in a street car.

Suggestion: I would get the intake gaskets with the blocked heat crossover to help with ethanol fuel heat soak problems. I would also get a 1/2" phenolic carb gasket to help keep manifold heat off the carb.


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## Dukes67 (Jun 19, 2018)

PontiacJim said:


> The '67 balancer is a 2-piece design. The '68 and up is one piece. You want to use the balancer that came with the engine as it matches the timing cover which is the 8-bolt style water pump.
> 
> https://butlerperformance.com/i-244...-dampers-59-67-pontiac-6-bolt-aac-630155.html
> 
> ...


Jim, I ended up getting the 2 piece balancer from Ames. The water pump I ordered from Flow Kooler is out of stock and 2-3 weeks out. I don't know how those car build shows get anything done in the time allotted, when everything is always multiple weeks out?! Thanks for the tip on the intake gaskets, I'll get them coming!


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Jim, I ended up getting the 2 piece balancer from Ames. The water pump I ordered from Flow Kooler is out of stock and 2-3 weeks out. I don't know how those car build shows get anything done in the time allotted, when everything is always multiple weeks out?! Thanks for the tip on the intake gaskets, I'll get them coming!


OK, sounds good. 

Those car shows are BS and just designed for a TV audience. I don't have cable or satellite (just good old rabbit ears - free TV) and don't get to see all the shows. When I visit family, I do watch some of them until I can't take any more of the BS they project.

Watched one show called Bad Chad Customs where he whips up the C-cab style pick-up truck for a raffle give away event he hosts. I think he did it in 10 days or something stupid like that. Picks up this old Ford flatehead engine and bolts it into the old chassis he just happened to have hanging around. Of course the engine fires right up after sitting what looks to be several decades. Hmmm, just dump a cup of gas down the carb and it lights right off. (I have a 1955 Packard out back that hasn't run in about 15 years, let's see him do that with it) Torches a rear axle out of a junkyard truck and the next day somehow it seeming is fitted under the chassis all bolted up and miraculously the truck is completely plumbed for a brake system. Then somehow the truck gets a wiring system from the overnight wiring gods and a fuel system from gas cans-r-us. Yep it all goes together, fires up, runs & drives and gets won by 2 brothers. Funny thing is that in the beginning of the episode Chad says he is going to do the C-Cab so a big guy can sit in it and drive the truck. One of the "big" brothers sits in the car and says "I fit." Hmmmmm. Little suspicious to me. I wonder if I gave him my '68 Lemans if he could have it completed and running in 10 days so I could take it to the next upcoming car show?

And then there is Counting Cars. What a jerk. What's up with the gangsta head bands that make you look like an idiot? Oh, let's just drive around the neighborhood and see what cars we might want to buy. OOOOOO, look at that! 1965 Studallac just sitting in the guys driveway that looks like it has a ton of potential. No one else in the neighbor hood ever sees it of course and when they go knocking on the door, sure enough, its for sale. How much ya gotta get for that rare car? Well, it was my fathers in 1968 and it is kinda sentimental so I can't really let it go too cheap. OK, but it will really need a lot of work like the interior is shot, the 426 hemi looks like it needs a rebuild, there is a little rust around the windows, and the chrome bumper is rusty. Ya, it needs work but I gotta get a good price. OK, how about $1500 dollars? Na, I can't let it go for that. I gotta get a lot more. OK, so what is your price? Man, I gotta have $3000. OK, we'll take it and I'll send my guy up here in the roll back and cash to get it. Hands shake.

Tell me how many neighborhoods you think you are going to drive through and spot an old car that just happened to be parked at the end of a driveway and the seller just happened to be in the mood to sell it and give it away at a stupidly low price that most guys would have wanted 10 grand for just the engine?

That's why I can't watch these show for too long. It is all BS. Then when the car is finished - they ALWAYS have a buyer willing to pay THEIR price and don't even quibble - OK, $250,000 sounds like a fair price. I'll take it. Yep, it's all BS. :yesnod:


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## Dukes67 (Jun 19, 2018)

PontiacJim said:


> OK, sounds good.
> 
> Those car shows are BS and just designed for a TV audience. I don't have cable or satellite (just good old rabbit ears - free TV) and don't get to see all the shows. When I visit family, I do watch some of them until I can't take any more of the BS they project.
> 
> ...


I just happen to catch these shows at the hotels when I'm on the road for work, no way in Hell would I pay for cable! It's laughable for anyone that has done this type of a hobby to watch these Soap Opera rebuild shows on TV with any real relevance to what's reality (I did meet Chip Foose though and I will say he was a super nice nice guy!). I'm glad that some of this has at least revived some interest in the younger crowd for the (ancients) 60-70 muscle cars.


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## Dukes67 (Jun 19, 2018)

It’s in!! Finally!! Thanks for all the advice from everyone. Car now has a 461 in it, 670 heads (ported) 30cc dished pistons, Lunati cam and a few other things. Still some dialing in to do but it should run. One question if anyone has run into this. I got a new oil pan from Butler and the clearance between that and the steering rods is minuscule. Has anyone else had this? Found a fix for it other than a different oil pan?


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## bigD (Jul 21, 2016)

Would recommend a taller air cleaner, if it will clear the hood. That filter may choke the engine down some. 

There are lots of drop base models that will allow taller filters. I'd consider a 14 x 3 as the minimum. 4" tall would be better. Also, some of the non-paper filters will probably flow more air.


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> It’s in!! Finally!! Thanks for all the advice from everyone. Car now has a 461 in it, 670 heads (ported) 30cc dished pistons, Lunati cam and a few other things. Still some dialing in to do but it should run. One question if anyone has run into this. I got a new oil pan from Butler and the clearance between that and the steering rods is minuscule. Has anyone else had this? Found a fix for it other than a different oil pan?



Looks great! Let us know how it runs, should melt the tires.

With the steering rod clearance, this has been pointed out in the past. Note the pitman arm is mentioned for PS which seems to drop the link a little lower. Here is a link to some forum suggestions - https://www.gtoforum.com/f50/my-wits-end-centerlink-into-oilpan-19247/

It could even be the engine mounts. Are they original rubber or aftermarket? Most parts that are aftermarket and claim to be "exact factory replacements" are really not. If me, I would check the trans mount to make sure it is correct, make sure you installed your crossmember/rubbers as factory so they are not too high and actually tilting the engine into the steering link. 

Found this, "I had this very problem on my GTO when I installed a Canton road race pan and the way I solved it was by unbolting the motor mount plates on the K-member and slipping a single 3/16" thick washer over each hole. I was surprised at how much this raises the engine. It's more than the thickness of one washer, that's for sure. Actually, I started with two washers and dropped down to one when I realized how much it lifted the mill.

I'm not sure this is an ideal method because it will affect the driveline angles to some degree (literally) but it did stop the centerlink from contacting my pretty gold pan."


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## Dukes67 (Jun 19, 2018)

Thanks for the insights. BigD the higher filters a no go, won’t fit. I do have an open sided can I can throw on. Jim, everything is stock. Mounts, steering, trans mounts etc.. The only thing that’s not is the “stock” oil pan from Butler and it is not the exact same as my original engine has on it. I think the engine mount spacing may be the only solution unless I can find a different style crosslink. Next question is I’ve been out running the engine today and it feels like the same if not less power than the original, completely stock tired engine had. I’ve checked timing (rebuilt,recurved distr.) and it’s at 12 initial/36 total, rebuilt the carb with what Cliff Ruggles sent me for the application and the thing feels weak. The engine was test ran on an engine stand and sounded great (unfortunately no dyno there) but it had a Holley carb on it. I got it home and threw on the Quadrajet and it runs ok but just doesn’t seem to be producing the power. Any good recommendations for remedies for this or a different carb for this setup?


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## bigD (Jul 21, 2016)

Make sure that your Q-jet is opening completely, when the pedal is on the floor. I've had to make adjustments, to get a full opening, on some cars.

"...the higher filters a no go, won’t fit..."

Does that mean that you have the lowest drop base that will work on your car, & that is the tallest filter that will fit. OR, is that just the tallest filter that will work with the particular base you have ? 

The reason I ask is that some air cleaner bases have no drop at all. They're just flat. Some have a little drop. Some have a lot of drop.


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## Dukes67 (Jun 19, 2018)

That’s the lowest (looks like it drops down, not flat) one I could find vs. the stock one without hitting the hood. It also has a low profile gasket under the carb with a stock Pontiac manifold. “The carb” I’ve played around with the secondary setting and it doesn’t seem to help. I don’t know what is going on with it? I’ve rebuilt (really just cleaning and gasket replacing) this carb in the past and it seemed like it ran fairly good on the old engine but now it starts, idles, and runs bad. I can’t seem to find anybody around Salt Lake that even knows what a carburetor is except at the small engine repair shop. So other than just understanding the basics like simple tuning (vacuum gauge for needle setting and adjusting the spring for secondary setting) I’m lost. It’s the original 67’ carb so I don’t want to do any cannibalizing to it for increased performance. So if it won’t work on this particular engine what after markets would be the best?


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Thanks for the insights. BigD the higher filters a no go, won’t fit. I do have an open sided can I can throw on. Jim, everything is stock. Mounts, steering, trans mounts etc.. The only thing that’s not is the “stock” oil pan from Butler and it is not the exact same as my original engine has on it. I think the engine mount spacing may be the only solution unless I can find a different style crosslink. Next question is I’ve been out running the engine today and it feels like the same if not less power than the original, completely stock tired engine had. I’ve checked timing (rebuilt,recurved distr.) and it’s at 12 initial/36 total, rebuilt the carb with what Cliff Ruggles sent me for the application and the thing feels weak. The engine was test ran on an engine stand and sounded great (unfortunately no dyno there) but it had a Holley carb on it. I got it home and threw on the Quadrajet and it runs ok but just doesn’t seem to be producing the power. Any good recommendations for remedies for this or a different carb for this setup?



The engine should have plenty of power with the bigger cubes by themselves. Start looking around for the obvious - bad gas from sitting, clogged fuel filter (or inserted backwards or did not use the spring behind it), look into the carb and make sure you get a good solid squirt of gas from the "squirters", make sure the accelerator pump rod is in the correct hole to give you the longest shot of gas, check to make sure that the secondary air flap is opening and that the lock-out mechanism has been removed, push the secondary air flap open by hand to ensure it is opening and not too tight on the tension, throttle cable pulling open carb fully? - have someone put the pedal to the floor while you look down the carb with a flashlight and hold open the secondary air flap. I have had the situation where the secondary throttle blades were opening up, but the secondary air flap above was not.

Exhaust could be choking the engine. 461 will want to breathe. Did you use stock exhaust manifolds and small pipes or go with RA cast exhaust and 2 1/2" pipes? You may want to test this out. Unbolt the pipes at the exhaust manifold, wire them up somehow so they don't drop to the ground, then take for a quick noisey spin around the block. You don't have to get crazy, but see if it responds better. Had a built 409CI that I had 2 1/2" head pipes running off the factory 2 1/2 " exhaust outlets just to take for a test drive. Engine ran OK, but I was not impressed based on what I had expected from a dual quad engine, big 2.19" valves, and a stout solid lift cam. My GTO at the time was more impressive. For some reason, can't recall why, I dropped the head pipes and ran the open cast iron exhaust manifolds only. Was like night & day. That engine came alive. Realized I needed bigger pipes. Went to a full 3" exhaust system and it never ran better.

Could be a few other things, but start simple. Check the carb/fuel delivery system first. :thumbsup:


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## Dukes67 (Jun 19, 2018)

Jim, thanks for the ideas. When I get off work this week I’ll try all of those. The gas is new (no ethanol gas with some octane booster). I’ll dig into the the valves when I get some time this week. I’ve got 2.5 inch exhaust with stock manifolds. If you were going with an aftermarket one what would you use? RARE RamIV’s?


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## bigD (Jul 21, 2016)

" That’s the lowest (looks like it drops down, not flat) one I could find..."


I can't believe that there is not a drop base that will allow you to use a taller filter.

Summit lists the distance above the base mount of many of the filters they sell. Don't know how accurate these specs are. But, you can see that there are some bases with lots of drop, up to 2". Some of 'em probably drop too much, and would need a spacer to make the base clear the carb/throttle cable/linkage. But, they make spacers, and you can use multiple gaskets to get the base high enuff to clear everything. 

https://www.summitracing.com/search...4294949603&SortBy=Default&SortOrder=Ascending


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## PontiacJim (Dec 29, 2012)

bigD said:


> " That’s the lowest (looks like it drops down, not flat) one I could find..."
> 
> 
> I can't believe that there is not a drop base that will allow you to use a taller filter.
> ...


Yep, I believe you can get a pretty good drop with some of the bases, but they have to clear linkages. A better idea, and from what I have read, is that the K & N top plates are a big plus in providing less restriction in air flow than just the paper element itself. This is how I would go - https://www.summitracing.com/parts/...MIg_y-_Z6X4gIVQoezCh2BHAi-EAQYAyABEgKm1PD_BwE


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Jim, thanks for the ideas. When I get off work this week I’ll try all of those. The gas is new (no ethanol gas with some octane booster). I’ll dig into the the valves when I get some time this week. I’ve got 2.5 inch exhaust with stock manifolds. If you were going with an aftermarket one what would you use? RARE RamIV’s?



Keep in mind that the engine is fresh and things have to seat and settle in. Check all the basic stuff first. Confirm your timing as it can move on you. 

I don't know if you went with the BigBlock Arp 7/16" rocker arm studs and polylocks on the rocker arms or not. This makes your valve train adjustable and you can "zero lash" the lifters to get the max out of the cam and ensure all the valves are closing as they should. If you went with the factory bottle neck rocker arm studs, the rocker arm nuts get torqued down to 20-25 ft pounds. It is possible that they can back off and may be something else to put on your checklist.

Yes, the RARE manifolds seem to be the best. A little pricey, but much better than all the problems with headers and in a HP comparison that has been posted here, the difference in HP is almost nothing. Better sealing, quieter, they will last forever, and less problems. I have not personally used them and on my 455 build, I am going with the ceramic coated Doug's headers. If I were building a little more of an original type street car that I wanted to drive a lot, then the RA exhaust manifolds would be my choice. 

Read these posts -
https://www.gtoforum.com/f154/ram-air-exhaust-manifolds-129514/

https://www.gtoforum.com/f12/how-choose-right-headers-87882/


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## Dukes67 (Jun 19, 2018)

Jim, it’s got stock rockers and those have been verified secure. Exhaust manifolds are ordered. BigD-The air filter could be a slight problem but even with it off it makes no difference in behavior. I checked the timing again and it’s still good. It acts like a carb issue?. I can’t find any vacuum leaks it’s at 18 (when it finally kind of idles). It may just be beyond my abilities at this point.


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## Dukes67 (Jun 19, 2018)

Finally starting to make some progress! Splayed open the carb again, pulled out the idle tubes, sized to .038 and voila it idles! Still feels a little sluggish but hoping the new exhaust manifolds will make an improvement. Ran a compression check all were exactly 140. Any other thoughts are much appreciated!


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Finally starting to make some progress! Splayed open the carb again, pulled out the idle tubes, sized to .038 and voila it idles! Still feels a little sluggish but hoping the new exhaust manifolds will make an improvement. Ran a compression check all were exactly 140. Any other thoughts are much appreciated!


You may want to increase the jet size. Did you notice what size they were numbered?

Cliff Ruggles Q-jet book has a lot of info for fine tuning. Simple test to find out if carb is running lean - idle engine at 2,000 - 2,500 RPM's at temperature. Then slowly "tip" in the choke by hand, but not enough to stall/choke out the engine. If it speeds up 50-100 RPM's (because the choke will richen the Air/Fuel mixture) then the carb is running lean. If it does nothing, the Cliff suggests removing one of the small hoses from the carb to allow additional air into it. If it speeds up, then the carb is too rich.


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## Dukes67 (Jun 19, 2018)

Finally found the lost Horsepower!! After fighting with this thing for the last two weeks I finally found the culprit. The vacuum with this Lunati cam is sitting at about 6 inches @ idle. While checking the timing it would show the the vacuum advance working but it was insufficient apparently to keep the distributor advanced while the car was in motion. I ended up putting a “slow bleed down” check valve between the carb and distributor and voila it runs!! It probably would have saved hours just switching to electronic ignition, but hey I’m apparently stubborn and just not that bright. Jim, BigD and others I really appreciate your insight into these cars and wish you all lived closer to talk to in person. If you’re ever out in Utah, beers are on me!


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## PontiacJim (Dec 29, 2012)

Dukes67 said:


> Finally found the lost Horsepower!! After fighting with this thing for the last two weeks I finally found the culprit. The vacuum with this Lunati cam is sitting at about 6 inches @ idle. While checking the timing it would show the the vacuum advance working but it was insufficient apparently to keep the distributor advanced while the car was in motion. I ended up putting a “slow bleed down” check valve between the carb and distributor and voila it runs!! It probably would have saved hours just switching to electronic ignition, but hey I’m apparently stubborn and just not that bright. Jim, BigD and others I really appreciate your insight into these cars and wish you all lived closer to talk to in person. If you’re ever out in Utah, beers are on me!



6" of vacuum sounds exceedingly low unless you have an all out racing cam with mega duration and lift. Are you sure no vacuum leaks anywhere? - vacuum needle is steady and does not bounce or waver. Check/retorque your carb studs and intake bolts.

You may want to set the idle mixture screws for best vacuum by adjusting them as you watch your vacuum gauge and see if you can improve the vacuum.

Now if all is good, they do make vacuum advance cans that work at lower vacuum readings. You could install one of these if you wanted. -- "Modified engines with more cam that generate less than 15” Hg. of vacuum at idle need a vacuum advance can that’s fully-deployed at least 1”, preferably 2” of vacuum less than idle vacuum level so idle advance is solid and stable; the Echlin #VC-1810 advance can (about $10 at NAPA) provides the same amount of advance as the stock can (15 degrees), but is fully-deployed at only 8” of vacuum, so there is no variation in idle timing even with a stout cam."

If you want to throw some timing numbers at us, we can take a look at what you have and see if there is room for improvement. :thumbsup:


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## Dukes67 (Jun 19, 2018)

Jim, I’ll try to get to the timing this week and bounce it off you. I checked the torque on everything today and everything was tight.


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## soberjoe (Nov 28, 2016)

Hey Dukes67, how did everything finally sort out for you?
I am awaiting the rotating assembly and HR top end kit from Butler for my stroker so I am reading everything that I can on the forums and I am curious as to what has transpired in the almost 2 years since your last post?

Joe


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