# Getting horsepower from a Poncho



## Docjim (May 8, 2015)

I know its kind of hard to get horsepower numbers from a Pontiac engine with after market parts. I was just wondering what you guys have found to be the best bang for the buck parts list to get horsepower. Carb, manifold, headers, cam, pistons???? What is your experience?


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## BearGFR (Aug 25, 2008)

Docjim said:


> I know its kind of hard to get horsepower numbers from a Pontiac engine with after market parts. I was just wondering what you guys have found to be the best bang for the buck parts list to get horsepower. Carb, manifold, headers, cam, pistons???? What is your experience?


There is no replacement for displacement. Stroke it.

Bear


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## Docjim (May 8, 2015)

WOw no one knows how to get horsepower from a Pontiac engine on this forum?? I guess it was harder than I thought


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## Goat Roper (Oct 28, 2014)

Push down on the skinny pedal on the right.
:smilielol5:


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## BearGFR (Aug 25, 2008)

Docjim said:


> WOw no one knows how to get horsepower from a Pontiac engine on this forum?? I guess it was harder than I thought


Ignoring the snarkyness for now ... 

There is a lot of information here about that. The thread search tool here is your friend. I reckon I know a little about it, my 69 GTO has functioning a/c, stereo, power steering --- and runs 11-second quarter miles e.t.'s. at a weight of close to 4000 lbs (including my hefty butt), with 3.50 gears and the TH400 doing its own shifting.

Pontiacs aren't like chevys. First of all, they make tons of torque down low. You don't have to spin them to the stratosphere to get them to move like you do with a chevy. chevy guys are always worried about making modifications that will kill their bottom end. Pontiac guys worry about how to get them to hook without murdering the tires. Building one is not like the chevy "chinese restaurant menu" approach where you just pick a bunch of aftermarket parts from among the selection of thousands available and bolt them on. You have to actually think and understand what you're doing. That's why we like them.

The information you seek is available - here and from other forums, and other sources such as these books:
https://www.amazon.com/How-Build-Pe...=UTF8&qid=1468932610&sr=8-2&keywords=jim+hand
https://www.amazon.com/Build-Max-Pe...&qid=1468932660&sr=8-2&keywords=rocky+rotella

The reason the first one is so expensive is that it's now out of print and hard to find, but still worth the investment if you're serious about learning.

Bear


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## 1968gto421 (Mar 28, 2014)

If you have trouble finding the Jim Hand book, member PontiacJIm, gave us this link to a series of articles Mr. Hand wrote for the Dallas club which includes much of his material from his book. Read all 16-17 parts to this great "freeebie" Here is the link:

Building A Strong Street Machine | Dallas Area Pontiac Association

You can also check out the Performance Years forum where it seems most of the guys are running between 500-600 hp on the street.

Here's the link: Pontiac - Street - PY Online Forums

This is a horsepower link there to get you going: Official Pontiac Street Engine Combo Thread, Post your combo here! - PY Online Forums

And DocJIm, do pay attention to Bear, he definitely knows what the hell he is doing when it comes to Pontiac power.


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## Docjim (May 8, 2015)

NOt trying to be snarky. I did use the smiley emoticon  Thanks for the help I will look at some of these suggestions


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## Red1970GTO (Jun 25, 2011)

*Indian Power*

 Do a Google Search of "Engine Masters Pontiac." You'll find a couple of stories about building Pontiac Engines for high performance. However, I think when all is said and done (and built) you'll discover why I daily drove Pontiacs, but raced Chevys...


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## PontiacJim (Dec 29, 2012)

Docjim said:


> I know its kind of hard to get horsepower numbers from a Pontiac engine with after market parts. I was just wondering what you guys have found to be the best bang for the buck parts list to get horsepower. Carb, manifold, headers, cam, pistons???? What is your experience?



Very generic question. Like asking what kinda woman makes the best wife? I think each of us has our own answer.

What kinda budget are you looking at? The bigger the budget, the more the horsepower. (the fatter your wallet, the closer you get to finding the perfect wife......just look at Trump :yesnod

So narrow it down for us. 
1) Are you looking to simply add more HP to your existing running engine, or are we talking complete rebuild?
2) Are you looking to reuse/retain most of your stock parts, ie crank, rods, heads, factory intake/exhaust manifolds, carb, etc.?
3) Do you plan on keeping your RPM's at stock levels, ie 5200-5600 RPM's or do you want to buzz your engine into the nether regions of 7500 RPM's?
4) Stock cubic inch or big stroker inches?
5) Iron heads or aluminum. Port/polish? 1.5 or 1.65 rocker ratio? Stamped rockers or rollers?
6) Flat tappet cam or roller? Solid or hydraulic? Low to mid range power, mid range to upper power or upper power?
7) Stock carb/manifold, tripower, aftermarket carb/stock manifold, aftermarket carb/aftermarket intake, singe 4-Bbl, 2 x 4 Bbl, low rise, medium rise, high rise?
8) Stock distributor/point, electronic conversion, electronic distrib., MSD?
9) Stock exhaust manifolds, RA manifolds, headers? Pipe size and muffler choices?
10) Turbo, twin turbos, supercharger, or nitrous?

Best bang for your buck might be a set of 4.11 gears. It'll make your car go like you added a lot more HP, but the down size is it won't be comfortable at highway speeds, excessive engine wear, and forget about any gas mileage......but you'll go like hell stop light to stop light.

So, give more details and perhaps we can narrow it down with you to get the range of HP you want. Keep in mind, more torque and HP puts more strain through the factory drivetrain and you may be popping parts or even cracking things. :thumbsup:


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## Docjim (May 8, 2015)

"Very generic question. Like asking what kinda woman makes the best wife? I think each of us has our own answer."


I had the top rated vintage snowmobile website a couple years back for ten years. I should have known better than to post this the way I did. Most questions like this have already been asked a few times and people that have been on the forum dont like to hash over it again and again. So I apologize if anyone was offended by the comment. I was trying to get some bang for the buck HP and thought some of members here that are very knowledgeable wouldnt mind. PontiacJim that is a big help

1. I going to rebuild but dont want to hurt reliability
2. I will retain the parts that I can but will change what I need too
3. RPM should be no more than 5500
4. Maybe bore but stock stroke
5. Iron or aluminum fine what ever works the best
6. What ever cam works the best, will replace it in the rebuild anyway
7. after market intake and carb
8. MSD
9. RA exhaust
10. naturally aspirated


Thanks again


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## 1968gto421 (Mar 28, 2014)

#1-- Try to fid a quality machinist in your area who is willing to listen and learn, and has a record of quality work. Goat Roper had a horrid experience with CVMS and had to have a local machinist help him save his engine. Check out the thread.

#2--You will get a majority of recommendations to go with after market forged connecting rods (RPM, Eagle, SCAT, etc.). They are cheaper than having your 50 year old rods eqipped with ARP bolts, sized, magnafluxed, etc.

#3-- Will save your engine's original parts that are re-used and save you $$.

#4-- Sounds good. Pontiac crankshafts are stout and will do you fine with stock stroke.

#5-- Do some research here. Members should chime in and provide you with good advice. Stock iron heads will flow around 211 CFM on the intake at .500" lift and should work with a 5500 rpm redline. Your best cylinder head experts are SD performance ( SD Performance- Pontiac Performance Specialists ) and Butler Performance ( http://butlerperformance.com/ ). Guys here can give you first hand knowledge of what worked for them.

#6-- This is a hot potato---like politics and religion. Here is a good link for you---- What Is Your Favorite Daily Driver Performance Camshaft in a 400? - PY Online Forums

#7-- The Edelbrock Performer has been found to flow less than the Pontiac 4bbl intake (1968-1972). The Edelbrock Performer RPM will do a great job as will the aforementioned Pontiac intake. Carbs are like cams---many likes and dislikes. On this forum the overwhelming choice is the QuadraJet 4bbl from GM/Pontiac version. If you don't have one handy, the Quadrajet guru is Cliff Ruggles ( Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuild Kits, Parts, Quadrajet Rebuilding, Quadrajet Parts, Bushing Kits, Carb Tuning ), also SMI is highly recommended ( SMI Carburetor Street Performance Rochester Quadrajet 800CFM Buick, Oldsmobile and Pontiac Quadrajet 4BBL Rochester 4BBL Quadrajet 800CFM for Pontiac SMI- Sean Murphy Induction ).

#8-- A great choice--I use a ready to run one. Don't forget to feed it a full 12 volts as the stock resistor wire from your ignition switch runs about 8-9 volts to avoid burning stock points. Other members will have their favorites and advise why that is so.

#9-- Good choice. Check out ( Factory Headers - Pontiac ). Remember D-port heads need D-port manifolds/headers and round ports have their own. For the street D-port heads will be best.

#10-- Engine lasts longer as does your wallet.

Luck!!


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## PontiacJim (Dec 29, 2012)

Docjim said:


> "Very generic question. Like asking what kinda woman makes the best wife? I think each of us has our own answer."


So I apologize if anyone was offended by the comment.

1. I going to rebuild but dont want to hurt reliability
2. I will retain the parts that I can but will change what I need too
3. RPM should be no more than 5500
4. Maybe bore but stock stroke
5. Iron or aluminum fine what ever works the best
6. What ever cam works the best, will replace it in the rebuild anyway
7. after market intake and carb
8. MSD
9. RA exhaust
10. naturally aspirated


Thanks again[/QUOTE]

No need to apologize, just too often the "generic" question on HP or engine building is asked and it really can't be answered in a way that is best for the asking - too many variables if you don't narrow it down.

I see you are no stranger to Pontiacs, so I imagine you have your opinions as to what you want to use in your build and are looking for recommendations to measure your build idea against others. OK, here goes.

You have a '67 400 which should have the 670 closed chamber heads if original. However, you are open to aluminum heads, so originality is not necessarily a must. 5500-5600 RPM's - good target RPM. Keep in mind any prices I provide may have changed, I'm just giving you an idea of where prices should be.

Rods. At a minimum, go with forged I-beam rods that are just like factory. You really don't need H-beams or bushed rod ends for full floating piston pins UNLESS you choose to. Best bang for the buck, $298 Butler Performance - Pontiac Connecting Rods

Pistons/Pins. The lighter the better. Now, keep in mind that you have to match your piston crown/compression ratio with your head choice/compression/valve lift. Typically for iron heads, the compression to shoot for is about 9.0 and up to 9.5 for a street engine and your cam choice has an effect on this as well, so cam choice has to be taken into consideration. For an aluminum heads, you can typically go 1 point higher in compression. Of course this is open for opinion and can be based on actual experience. I have read some retain the 10.5 compression ratio with no detonation problems, but going off of *geeteeohguy*'s years of running his car, you will need an octane booster to add to your high octane gas - so it is your choice based on what kinda gas you want to use and how often you may be driving the car. One of the keys to going on the higher side of the compression range is your cylinder quench area, I like .045" as my machinist explained that forged pistons will expand, .040" may be what other say, but he believes and builds the quench at .045" - more for turbo, nitrous, supercharged, & race. So this applies to an NA engine. Stock deck height is typically .020" = 5cc's. To get the .045" quench as I did without milling the block (zero decking it), I went with the Cometic .027" head gaskets. Most "kit" gaskets are about .040" which will put your quench at .060" - like factory. Will also lower compression a bit. Something to think about.

Butler offers Ross pistons, but, *in my opinion*, are as advertised - Racing Pistons. These have the 1/16" rings which I feel are again more suited to race. Some of their lightness comes from a shorter piston skirt. Shorter piston skirts MAY allow the piston to rock in the bore, so it seems to me this may be OK for a high RPM race engine, but not for a street car. Butler Performance - Pontiac Pistons

Next choice, and what I purchased for my yet un-assembled 455, is the Keith Black ICONN forged piston. Light, great quality, use stock sized rings - 5/64". If you use your 670 iron heads (one of the best) the closed chamber shape is that of a "D" shape and the ICONN pistons are offered in a "D" shaped dish which would mirror your chambers in shape. I did some quick number crunching using this Pontiac compression calculator, .030" overbore, .020" piston down in the hole, .027" head gasket, 14cc D-dish ICONN piston, 72cc 670 heads and get 9.6 compression - Classical Pontiac Compression Calculator However, getting your heads to 75cc's yields 9.36 which would be about perfect. You heads may or may not be 72cc's as they can actually be more by a few cc's. So you need to cc your heads first, talk with your machinist as to what he can do to get you near the 75cc range, and the ICONN pistons - *in my opinion*, is the best bang for the buck. Here is the catalog online, check out page 3 for a D-Cup (Dish) piston to see what I mean. Shows quench area as well. https://www.uempistons.com/catalogs/icon_catalog.pdf

Of course the Federal-Mogul (formerly TRW) has always been a great choice for forged Pontiac pistons, but, these are flat tops with typically 6.7 cc valve notches, so you'll have high compression near factor specs.

Many other manufacturers as well, its a real gambit, from stock cast to high dollar forged.

Heads. The 670 iron heads are great. One of the best intake flowing heads of the D-port heads. Closed chamber is not ideal as in '68 they went to open chamber which is better. BUT, 670 heads are still good to use. Big valves,screw in studs, push rod guide plates, oil drippers. For 5500-5600 RPM's, I would use Ferrea stainless steel valves, new springs & retainers, new bronze guides, valve seals are basically a personal choice & one you can make with your machinist, 3-angle valve job, port match the intake side, a clean up of the runner walls to remove any casting lines/irregularities -but keep the walls rough, not polished. Deburr any flashing in the heads where the oil returns - smooth things out for better oil return. I would not do anything to the exhaust side except grind down any irregularities/casting just to clean up a bit. Use a set of Comp Cams 1.5 stamped rocker arms and use a pushrod checking tool to get the correct length pushrod for your engine - COMP Cams® - Pushrods

Aluminum heads are a great upgrade and there are Edelbrock or KRE or Wenzler. I am not that versed in their use as I have never owned/used a set, so no experience. Advantages are better cooling, can go higher compression, flow better than stock iron heads right out of the box, can handle bigger lifts, can be repaired if they get damaged by flying apart pistons/valves, are complete and ready to go. Down size - cost. Not the best bang for your buck *in my opinion*, but if you price the costs to rebuild and do the machining work on the 670 heads, it may be a consideration to up grade with a little more money if you can and are not too worried about original numbers matching heads. The key here is to have an intake port sized to keep up the air/fuel velocity. These heads flow about 270 CFM's out of the box which is great for mid/upper RPM's. Seeing you are looking at 5500-5600 RPM's I like the iron heads for their lower flow because velocity will be good at lower RPM's through the upper mid RPM's to right where you want o max out, so crisper throttle response. If you want 6000-65000 RPM's then the aluminum heads are the way to go.

Camshaft. Lots of opinions on this one and lots of info on the forums. I like the factory cam specs or some enhancement of them. The 068 is one of the best all around street performers and suits your RPM range. The 041 pushes the RPM band up and would be a bit high for your RPM range and sacrifice lower RPM driveability, but, if you went with Rhoads Lifters, these would tame it down under 2500 RPMs and then give you more power up to your 5500-5600 RPM range (and keep going if you wanted to). Use with 1.5 rockers and not 1.65 as used by the factory. With the head work on the iron heads, you may want to go a tad bit more on lift .470-.480" on intake and .500" on the exhaust (like the RA IV with 1.5 rockers) while still using the stock height springs/valve combo. Your machinist will let you know at what height your stock valve springs/valves will go into bind OR you can use the longer RA IV valves/springs to get close to a .580" or so lift - which you will never need on a 5500-5600 RPM engine. DO NOT use a 110 LSA cam as these typically work best in under 9.0 compression, even better in the 8.0-8.5 in my opinion. So keep your LSA between 112 & 114. Roller cams/lifters are best, but cost way more, and will have different specs than a flat tappet. Never had a problem with a flat tappet cam, but I have never gone crazy with high lift or high spring pressures. Here is a nifty guide you can use - Selecting a Hydraulic Cam for your Pontiac Engine

Now the BIG KEY here is Dynamic Compression ratio. Use the Wallace Dynamic Compression Ratio Calculator to get handle on this. Wallace Racing: Dynamic Compression Ratio Calculator The thing most important in selecting a cam is the cam's intake closing point *A*fter *B*ottom *D*ead *C*enter (ABDC). This is always found on the cam card or cam spec. You want a *Dynamic Compression* ratio of less than 8.0 with 8.0 being a little high for the street. I selected a solid cam for my 455 build, with my *Static Compression* ratio of 9.2, which is right at an 8.0 *Dynamic Compression*. It may work fine, or it may be a little too much and I will have to play with the cam timing to fine tune-it. Never used this info in any engine build in the past because I never knew anything about it. So I am on a learning curve on this one and wont' know until I actually get my engine together and test drive it. So suggest you do a little reading from off the internet as I did to get an idea of what this is.

RA cast exhaust manifolds :thumbsup:

MSD add-on to the factory points distributor OR go electronic and MSD. What ever you select, GET a REV-LIMITER to save your engine should you miss a shift, get your tires really smoking, or simply spinning tires on wet/icy/sanding roads. :thumbsup:


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## bigD (Jul 21, 2016)

"... trying to get some bang for the buck HP..."


My opinion on getting the most bang for the buck power(using a stock crank), would be to start with a good rebuildable 455. 

(1) Use Speed-Pro L2359NF30 forged pistons with RPM brand 5140 forged rods. If you have the budget for it, you can upgrade to light pistons, such as Auto-Tec brand(or Icon) and the RPM(or Eagle) H-beam rods.

(2) Either buy some ready to run, or good 6x-8 iron head cores. These heads, even unported will make 400 or more pump gas hp, and near 500ft lbs of torque, on a 455. You need one piece stainless valves, 7/16 rocker studs, and have 'em built by somebody who knows Pontiac heads. But, if you have the budget for 'em, either Edelbrock or KRE alum D-port heads are better than iron heads. 

(3) My choice for a 455 cam is an 041 grind, such as a Melling SPC-8 or Crower 60919, WITH Rhoads lifters. Without Rhoads lifters I'd run either a Howards #410051-14 or a Crower 60243. The Summit 2802 would be the cheapest cam, with decent specs for a 455. If your budget can stand it(at least $1000 more), it has been proven that the correct roller cam will make more power than a flat tappet cam. 

Here are examples of aprox what I'm talkin about. Can be built with different options.

455 Long Block

455 Short Block


"...7. after market intake and carb..."

I'd go with a GOOD 800cfm '77-'79 Q-jet. SMI is considered one of the best sources. 

http://www.smicarburetor.com/products/sfID1/28/sfID2/9/sfID3/100

If you prefer a square bore carb, a Quick Fuel SS-680-VS or larger, may be a good choice.

http://www.gtoforum.com/f178/opinion-carberater-400-motor-86857/index2.html#post624025

http://www.gtoforum.com/f178/opinion-carberater-400-motor-86857/index3.html#post624121

http://www.quickfueltechnology.com/carburetors/street/ss-series/

For a 400, a dual plane intake is best, and a factory iron intake is plenty good. For a 455 or larger, a single plane will work just fine. The cheapest new intake is a Chinese single plane. This intake will accept either a Q-jet or a square bore type carb. 

http://www.ebay.com/itm/Pontiac-326...ash=item2ef1e9d844:g:BxIAAOSwFfhXjbmm&vxp=mtr

If you go with a square bore carb, the Torker 2 intake works good on a 455. An old Holley Street Dominator is said to be OK on a 455, with a Q-jet.

http://www.ebay.com/itm/Edelbrock-5...ash=item19de470eae:g:HdwAAOSw5dNWjUrZ&vxp=mtr

http://www.ebay.com/itm/Holley-Stre...ash=item25bfc9d166:g:XOcAAOSwYSlXgUXi&vxp=mtr

The RPM intake will also accept either type of carb, and is a dual plane. But, they're nearly $300 new. There is a cheaper Chinese 2-plane. The Chinese intakes do not have an exhaust heat crossover. And, some say they may need a little more port matching than some of the USA made intakes. 

http://www.ebay.com/itm/Pontiac-326...ash=item281c8d3d7a:g:2DEAAOSwj2dXjbj6&vxp=mtr


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## Pinion head (Jan 3, 2015)

What are the GOALS of the car's build? 

-Cruiser, must be able to drive the highways at highway speed without overdrive and the luxury of 93 octane fuel at every fillup?
A lot of Pontiac guys on the Net love to recommend builds suited for minimum of 93 octane fuel, but having again this summer driven all over the country, 91 octane ethanol laced junk gas is often as good as it gets.

-Occasional street driver? 
can tolerate a little more gear, like 3.31's to 3.55's with a 26.5" -27" tall tire? Not going on any long interstate trips.

-Local performance driver, seldom on the highway... This would be the easiest and least expensive route to go with a 400 utilizing 670 heads (open chamber mod, proper street ported). going to need gear (3.73's-3.90's) and fairly large HFT cam or small roller cam. With a 406-413, power increases are going to be in the 3500-6200 range. A 5500 rpm limit makes no sense.

To make easily streetable combination with a serious power increase, over stock, the 3.75 inch stroke is a limiter. 380-400 horse can be made fairly easily with a streetable 400 combination, but much more than that is going to be tougher with something mild mannered to drive. Whatever build, I would recommend a good set of forged rods and light affordable pistons like the AutoTecs. Don't get caught in the trap of ordering the standard bearer Fed mogul Sealed Power forged 400 pistons that will be .020 in he hole to begin with.


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## PontiacJim (Dec 29, 2012)

PH: "What are the GOALS of the car's build? "

bigD:"My opinion on getting the most bang for the buck power(using a stock crank), would be to start with a good rebuildable 455."

Docjim has a 400CI under the hood. He has already stated on page 1 of the thread what his goals were with regards to the engine build:

1. I going to rebuild but dont want to hurt reliability
2. I will retain the parts that I can but will change what I need too
3. RPM should be no more than 5500
4. Maybe bore but stock stroke

That said, he is looking for advice/opinions based on his 400CI engine, which I assume is factory until Docjim says otherwise. So lets give him advice based on a 400CI. :thumbsup:


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## Pinion head (Jan 3, 2015)

PontiacJim, I have been on the road and attempted to respond to this post earlier yesterday, and it would not post on my phone. Not one respondent asked those salient questions! The initial post gave a good idea the fellow did not know much about Pontiac V8's. This series of posts has again tanked into an a shotgun pattern of responses, with your input, though its yet to crash into how you would recommend hacking up the tunnel for a Tremec swap or contrapting a Ferd rearend into the car 

Not once has DocJim noted what he required driveability wise out of the vehicle. He did note in the opening topic, how to make more hp. It's one thing to put a 5500 rpm limit on power production in a 455 derivative, it's something else to do so with a 3.75" stroke build. I've built numerous street usage cast iron head 400's that made over 400 hp, they required a couple of gallons of race gas to bouy the octane and for a small degree of lead for the valve seats. They also required a lower final drive ratio, not 2.93's, 3.08's, 3.23's, 3.36's.


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## Docjim (May 8, 2015)

Great advice! now thats what I need! Thanks Guys!


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## PontiacJim (Dec 29, 2012)

PH, all too often these topics can get side tracked and next thing you know we are talking about rear end swaps and trans tunnel hacking. I look at it this way, if we can keep the focus, then each topic lends a wealth of information and tips, plus a perspective from all corners, that can be accessed by others here or on the web who in the future may be looking for the same answers. Your input is always valuable and often times more exacting, informative, and fact based more than most - I am by no means an expert nor handled the amount of parts you have physically gathered or researched, and I have always maintained my position as an auto enthusiast with a lot of varied experience in many areas, but have always favored and owned Pontiacs when possible - many in my youth.

I am also a good researcher and have collected a good many books/pamphlets on Pontiac build-ups, some being privately published when they used to sell these out of the back of car magazines when I was younger and doubt many people own them as I do. I took a look at Docjim's previous postings as we all can do on each one of us. By reading his past posts, it gave me a little background that indicated he knows how to work on cars/engines, info on his car, and what he was looking to do. Although Docjim could have gotten a lot more specific in his initial post which would have helped those who look to help and add our input, he did, after being asked, provide enough info to deduce what it was he was looking for. (Maybe we need to have a profile rating number system, 0-5, engine building/wrench turning skill levels so we have an idea of the mechanical aptitude of the person posting the question). 

Based on what he did give us as a set of parameters, it would seem the end game was the best bang for the buck rebuild of a Pontiac 400, a street engine with options for upgrades if they fell under the best bang for the buck. Like you, I think the 380-400HP range is doable with the 400/iron heads, and 5500 RPM limit he put on the engine, and be pump gas friendly(dependable) with a little lower compression with of course an aim on good torque numbers and broader power band for the street. 

So in my opinion, which it only is, heads, correct cam selection, & exhaust are key moreso than anything else in waking up a Pontiac engine. At 5500 RPM's cast pistons/factory rods with ARP bolts will work, but upgrading if affordable to the builder is never a bad investment. The rap on Pontiac rods being a weak link has not been proven other than the factory rod bolts were the only thing I have ever read as concrete evidence in being a cause to the bad rod syndrome - factory rod bolts stretched at higher than factory RPM limits, causing the bearing halves to pull inward at the parting line, scraping the oil film off the journal, and causing bearing failure at high RPM's. Even the higher revving RA engines used cast rods. But, to resize,rebuild,ARP them, might just as well go new aftermarket forged - best bang for the buck. Can't go wrong with the Q-jet/factory intake, so no need to really change this - best bang for the buck in my opinion. Although in one of Docjim's posts, seems he may have already tried the QF SS-680 carb that bigD mentioned. 

Again, with an imposed limit of 5500 RPM's for a 400CI, I think it boils down to the three things I listed, heads, cam, & exhaust upgrades/mods to really wake the engine up and provide the best bang for the buck. My guess is that you can throw some of your experience with suggestions for the same as we all build/have built engines in a manner we feel is the way to go in searching for HP without breaking the bank.


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## Pinion head (Jan 3, 2015)

PontiacJim, I simply posted 3 different genre's of builds. by identifying what genre one IDs with with their vehicle, it speaks volumes as to what specifics are needed in the build.n No response from the OP in that regard. 

From making first post on this topic, knew the owner has a '67 400, possibly with "'670" heads. Have prev rebuilt 400's with 670 heads, one has to take into consideration what fuel is avail. I've come in late and helped numerous locals that thought they had their '67 400's rebuilt right just by doing a quality rebuild and springing a little more for TRW/Sealed Power 2262's. Consistently, that piston sets a little lower in the hole, just like most cast rebuilder pistons. Most average price Pontiac builds, the machinist doesnt zero deck the block. New 400 pistons down in the hole .020 or more, timing backed out, carb running rich, engine runs hot. Such a common problem, questions get asked about it nearly evey we month on forums. 

Again, we have no idea what rear gear ratio is in this '67, or what is the intended use. Most importantly, we have no idea what octane of what fuel us avail at the pump for the OP. Some of us have no issue buying and storing a drum of race fuel to mix, for most, tht is not an option.

Throwing things to the wind... if the OP has the interest and the funds, personally, I would suggest he contact Dave Bisschop @ SD Performance and have him detail any advantages to his CNC open chamber mod to the 670 heads vs running a well designed dished piston. Dave could also suggest a cam for his intended engine/drivetrain combination. 

Know what HO Racing cam I ran 31 years ago in my streetcar with a 85 cc open chamber street ported 406 that with cheapy used Hedman headers 2 1/2 head pipes and sonic turbos ran 12.62-12.65's @ 108. I doubt the OP is interested in running a 3.90 gear and a loose converter. technology has changed in respects to converters, many other parameters like a 400 with X sized cam and Y sized head flow has not changed.


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## Docjim (May 8, 2015)

There is one thing I forgot. I want it to look pretty much stock under the hood. The car has 66000 original miles and I dont want to take away from that. I dont mind a different carb and intake because I have the original I can display. Thats why I like the RA III exhaust. Could info here. Thanks again dudes!


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## PontiacJim (Dec 29, 2012)

Pinion head said:


> PontiacJim, I simply posted 3 different genre's of builds. by identifying what genre one IDs with with their vehicle, it speaks volumes as to what specifics are needed in the build.n No response from the OP in that regard.


It would be nice, and I think you would agree, that we need a couple "sticky's" that wold really help those who need advice and those who provide it.

1.) A checklist of questions (just like you would use in selecting a cam) in rebuilding/upgrading/or target HP range that the poster is looking for. The checklist would help the poster in being specific in what it was he/she was aiming for and in turn it would help those who make the attempt to fulfill the desire. Sure would leave out a lot of guessing by us and target the build to suit the need.

2.) Another 2 "sticky's", except these would not be open for discussion as most topics are. These would be close by an administrator and can only be opened and added to by an administrator. 

I would love to see one "sticky" having the Topic *326,350,389,400 Engine Builds* and the other "sticky" having the Topic *421, 428, & 455 Engine Builds*. 

Now these builds would be submitted to an administrator and posted by same. They would be our suggestions either by design or through actual engine builds; personal or others. These engine builds could either be a complete engine, OR target specific assemblies, ie carb & intakes, heads, & short blocks. What it would not include would be a specific part, ie best piston, rod, valves, or individual carb or intake. The specific assemblies would have to be just that, a complete combination that works together as a unit.

In this way, each of us who has input as to what makes a good recipe for a complete engine - horsepower & torque range - or has a good recipe in putting together a specific assembly, could do so. If one of us strongly disagreed or spotted an error, we could contact the administrator, voice our concern, then the admin. would pass the info on to the original poster for his/her opinion as to support the build/assembly in question or recognize an error. Might simply be a typo, misinformation, wrong part/part number, etc.. This would provide a means to clarify, have changed, or get corrected anything in any one of our posts that could inadvertently misdirect someone who did not know any better and was using our info as a basis for their engine build. 

I think this type of "sticky" would make a great resource for anyone who is looking to rebuild/build-up/or upgrade their Pontiac engine, whether novice or the experienced. Think about all the knowledge/experience many of us have in working on these old Pontiac engines, whether it be a simple stock rebuild or balls-to-the-wall tire shredder. We won't be around forever, but our cars might. 

There are so many new owners all the time to the first generation GTO/Pontiac muscle cars who don't know much about that Pontiac engine under the hood nor do many of their friends or local parts suppliers/machine shops/repair facilities. Without this knowledge........they go LS engines because they are better understood, 2nd Gen GTO's use them, easier to source, have good HP & torque numbers, and are so generic that any machine shop can build one. But if some of these "newbies" understood what a Pontiac engine has to offer and how to build it, they might be more inclined to go with that Pontiac engine under the hood or source one out to build up, rather than take the easier and popular route and go LS due in part to their, and others, ignorance in not knowing the Pontiac potential.

3.) Same goes with things like rear axle assemblies - to which you have really added to that conversation. Based on HP/Torque, manual/automatic, gearing/tires, & intended use, different levels of what would work and what would not would most likely be a great help to those owners who start modifying. Nothing like a guy building a 500 HP/525 ft lbs of torque stroker and dropping the hammer on his stock 50 year old 10 bolt and having it grenade. Then the taste left in his mouth, and his first impression, is that Pontiac's suck because they make cheap rear-ends because his engine builder, nor anyone else, thought past the big HP he just dropped into the engine bay.

These are the things I feel are needed to keep these first Gen Pontiacs going and provide a solid means of rebuilding/upgrading through forum advice by those who have the experience and/or knowledge in doing so - because we were there or because we are the types who simply work on them ourselves, regardless of age. And if we don't, the Pro-Mod betterment's take over those stock components, the LS engine conversions become more mainstream, Hot Rod thinking takes over, and the first Gen GTO's slowly devolve into Chevy Chevelles. :banghead:


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## Docjim (May 8, 2015)

PontiacJim WHen I ran vintagesleds.com I would contact the guys that were tech gurus that knew there stuff. A couple I made moderators in the tech section. They always offered great advice to tech questions and are still doing it today. I would also contact a member with a PM now and then and thank them for advice to other members. Being moderators kind of made them important and respected and they appreciated it.


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