# 67 GTO 400 rebuild



## Fxnjetz56 (Mar 21, 2015)

So, not sure if it’s bad breath...? Poor forum etiquette...? Un-interesting posting...? Not much response to my past inquiry about engine project...but I’ll try it again anyway...

I have a quote for a rebuild/upgrade for a 400 YS motor, that includes this roller cam Comp COM 51-423-11. Any thoughts with regard to this unit? I’ve read much of the debate roller vs. flat tappet, I’m not necessarily opposed to roller, but not sure I have an overriding need to go that route for a street motor.

I had some discussion with the shop owner with regard to what I was looking for. Overhaul motor, machining as needed. upgrade to include new forged rods and pistons. Lowered compression to 9.5:1 or less. Cam to something similar to an 068. I used an XE262H as an example.

He’s not fond of flat tappet cams, hence his recipe with the roller. He seemed truly puzzled at the notion of dropping compression below 10:1. He told me 10 is fine for cast iron heads, 11 for aluminum. The quote for this engine complete with Dyno break in and tune comes to just a north of 9k.

I’ve talked to all the other likely Pontiac builders in and around Chicago...they’re at 6 months lead time, some aren’t booking new work until next year.

Found a builder called Tri-Star up in Wisconsin...they are well recommended on line, have about a 2 month turnaround to overhaul/build a long block to my spec.

I also have a call in to Len Williams for his 400 long block availability.

Having work booked out the door isn’t a bad problem to have I guess...just a little frustrating when you’re on the other side...


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## Old Man Taylor (May 9, 2011)

What do you want out of your engine, what heads are on the engine, and what head work do you plan on having done? I am also a proponent of trying to keep the CR on iron heads at 9.5:1 or less.


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## Fxnjetz56 (Mar 21, 2015)

Old Man Taylor said:


> What do you want out of your engine, what heads are on the engine, and what head work do you plan on having done? I am also a proponent of trying to keep the CR on iron heads at 9.5:1 or less.


OMT,

thanks for your response...

its a YS code engine (335 hp) 670 heads with th400 trans/3.23 open rear, power drum brakes, p225 70R 15 tire.

all I wanted out of the motor upgrade was just the basic overhaul (had a rod knock, rear main oil leak and 20 years since last rebuild) and to make it pump gas friendly, maybe increase hp and torque a bit At the same time.

I didn’t plan on doing any head work beyond having them checked, and a fairly standard valve job, new valves/seats/guides/seals etc. 

Im planning on replacing the edelbrock performer/Holley carb with a 1968 stock intake/quadrajet. Not sure porting, or even port matching is required, nor cost effective as long as the block/heads don’t require any radical decking.

Not a racer, just an old dude with an old GTO...Summer Cruiser, and maybe my only remaining vice....


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## Old Man Taylor (May 9, 2011)

Then I would go with the cam you selected.


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## RMTZ67 (Mar 12, 2011)

I rebuilt my engine about a year ago. kept my Iron heads and 068 cam....and brought my compression down to ??? somewhere around 9.5:1. I would have to look at my notes/post. If you like, you can look up my post "cracked my 400 this is what I found"


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## PontiacJim (Dec 29, 2012)

Fxnjetz56 said:


> So, not sure if it’s bad breath...? Poor forum etiquette...? Un-interesting posting...? Not much response to my past inquiry about engine project...but I’ll try it again anyway...
> 
> I have a quote for a rebuild/upgrade for a 400 YS motor, that includes this roller cam Comp COM 51-423-11. Any thoughts with regard to this unit? I’ve read much of the debate roller vs. flat tappet, I’m not necessarily opposed to roller, but not sure I have an overriding need to go that route for a street motor.
> 
> ...



Here is your engine post that got an answer, but sometimes you have to be persistent or "bump" your post as these posts get buried by other posts due to the poor listing set-up this website uses. It used to be much better, they they had to go and try and improve it - not.

So here are your choices for your build as you posted them:

Planning Overhaul with:

Thermal clean/mag check block and heads
Valve job to include new stainless valves/seats/guides/seals/springs as appropriate
Bore/Hone .020 (torque plate)
Deck Block/Heads minimum required to flat
Cut/Polish/Balance Crank and rotating Assy
Forged Speed Pro pistons dished for 9.3:1
Forged I-Beam rods
Comp Cams XE262H
Roller Tip rockers 1.5:1
Stock 1968 Quadrajet intake
SMI Stage 1 800 cfm Quadrajet
Ram Air Exhaust Manifolds 2 1/2” exhaust

OK, lets break it down.

1.) Thermal clean/mag check block and heads - YES
2.) Valve job to include new stainless valves/seats/guides/seals/springs as appropriate - Yes, but install 7/16" Big Block Studs to replace the factory "bottleneck studs" which are prone to snap with higher valve spring pressures/lift, BBC studs means poly locks to adjust the rocker arms, Pontiac uses different length valves - use Ferrea Stainless stel valves and decide valve length to ensure you have enough stem length for a higher lift cam if so selected, have the intake passage inlets gasket matched (you can do this yourself), clean up the intake passages of any rough parting lines & "burrs" (you can do this yourself), get a 3-angle valve job, bronze valve guides, Viton valve seals which means cutting down the valve guides for fit. Upgrade to new stamped 1.5 rocker arms for a more accurate rocker arm ratio. These will have an elongated slot at the rocker stud for higher lift cams so they don't bind, They also come with grooved rocker arm balls for better oiling. You DO NOT need roller tip rockers or full roller rockers for the street.
3.) Deck Block/Heads minimum required to flat. Are you talking about "zero decking" the block so the pistons are flush with the bock at TDC? or just checking for squareness/straightness? Zero decking can be OK, but this will have a bearing on compression, so you have to know if "zero deck" or stock which puts the piston about .015"-.020" down in the cylinder. The heads don't need any big cuts, just light touch to ensure a flat surface.
4.) Bore/Hone .020 (torque plate)
Cut/Polish/Balance Crank and rotating Assy
Forged Speed Pro pistons dished for 9.3:1
Forged I-Beam rods
Purchase a Butler stroker kit/assembly - best bang for the buck and includes all these parts in the kit and far cheaper than individual part purchases - 461 cubic inches so you can pull extra HP/TQ and keep the engine very streetable with a mild build. Once you know the bore size the block cleans up to, then order the matching pistons which will be Ross. At the same time, get the tops of the pistons cut to match the closed chamber shape of the "670" heads and the correct amount of dish to give you 9.5 compression. With closed chamber heads, you can go 9.5, but 9.3 is good if you want to go with it. Let Butler know what you have and then they should be able to provide the specs for the piston as needed, or other recommendations.
5.) Roller Tip rockers 1.5:1 - Covered this earlier. Not needed, save money.
6.) Stock 1968 Quadrajet intake & SMI Stage 1 800 cfm Quadrajet - Good Choice
7.) Ram Air Exhaust Manifolds 2 1/2” exhaust - Good Choice
8.) Roller Cam - NO, don't need it for a street car. Save your money. If you do you go roller, you need a lifter galley brace so you do not take the chance of busting any lifter bores with the roller cam/stiff valve spring pressures. Hydraulic flat tappet cam is fine, don't get BS'd into all the fear tactics of using one. The factory 068 cam is always a good choice. There are other cams as well. DO NOT select a Comp Cams cam (or any other) having a 110 LSA spec. These cams will build/raise cylinder pressure and not what you want when lowering compression. If you had a, 8.2 compression, then 110 LSA would wake it up nicely. The wider the LSA the better the vacuum if you have power brakes. The more duration you select, the higher up into the RPM range you have to spin the engine to take advantage of it and you sacrifice some bottom end grunt. Not a good pick for a stock automatic and 3.23 gearing.

9.)Use a good cam break-in lube on the lobes like a paste which won't drip off if the engine sits at all. I have not used this, but I will use soke form of a break-in paste on my hydraulic solid lifter cam/lifters. Here is just one example:









Isky Racing Cams RL1 Isky RevLube | Summit Racing


Free Shipping - Isky RevLube with qualifying orders of $99. Shop Assembly Lubricant at Summit Racing.




www.summitracing.com





10.) Milling heads/block will most likely require new pushrods as the length may need to be adjusted to get correct rocker arm geometry.

11.) Keep quench/squish around .040"-.045" which is easy enough if you zero deck the block and use the Felpro head gaskets which compress around .041"-.042".

12.) I like the addition of ARP main studs, but the factory main cap bolts are heavy enough. If going ARP, then you will have to get the mains line honed after installation.

13.) Use the Best brand graphite rope rear seal.

14.) Use the Butler blueprinted Pro 60-PSI oil pump. You do not need or want the 80 PSI pump.

15.) Use a 15W-40 oil, not 20-50W. You may even be able to use 10W-30 depending on bearing clearances, but 15W-40 is my choice for a HP street engine.

16.) New Harmonic Balancer to replace the old dried out rubber inertia ring.

17.) New water pump divider and sleeves and clearance the impellar to the divider.

18.) Distributor? Make sure it has the vacuum advance feature - do not eliminate this.

19.) Save money on the roller cam set-up, roller tip rockers, and invest it back into the Butler stroker kit.

Install a "tight" 2,500 stall converter. It will have little slip during easy throttle and crusing. Nail the gas and it'll come alive. Doesn't put the extra heat into the trans like a "loose" 2,500 converter.

How did I do??????


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## Fxnjetz56 (Mar 21, 2015)

PontiacJim said:


> Here is your engine post that got an answer, but sometimes you have to be persistent or "bump" your post as these posts get buried by other posts due to the poor listing set-up this website uses. It used to be much better, they they had to go and try and improve it - not.
> 
> So here are your choices for your build as you posted them:
> 
> ...





PontiacJim said:


> Here is your engine post that got an answer, but sometimes you have to be persistent or "bump" your post as these posts get buried by other posts due to the poor listing set-up this website uses. It used to be much better, they they had to go and try and improve it - not.
> 
> So here are your choices for your build as you posted them:
> 
> ...


Awesome Sir, thank you for your time and attention to detail. Not like I'm unfamiliar with going down a rabbit hole now and again...but this...is a rabbit hole within a rabbit hole...inside another. Ive been scouring the forums, and have found so many different opinions on what works. I am beginning to at least identify some common denominators between all the varying opinions...Detail like yours surely helps. Thank You!


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## BearGFR (Aug 25, 2008)

That item that Jim mentioned, "4.) Bore/Hone .020 (torque plate) " is super important and make sure that you "grill" the machinist about it. I live very close to the Dallas/Fort Worth Texas "Metroplex" (I call it the Metro-mess) of 7.5 million people and growing steadily every single day with a few hundred families moving in _every single day. _ Even with all the engine shops and machine shops there and within 100 miles of there, there is a grand total of 3 and only 3 shops that even have a Pontiac torque plate at all. If your shop tries to tell you that "Pontiacs don't need one" - dump them. 

I ended up buying a torque plate for myself just to open up some options for having work done, and even then it took weeks to get it. I had to wait for the supplier to MAKE it because there's so little demand for them now. They aren't cheap.

Bear


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## michaelfind (Dec 14, 2018)

BearGFR said:


> That item that Jim mentioned, "4.) Bore/Hone .020 (torque plate) " is super important and make sure that you "grill" the machinist about it. I live very close to the Dallas/Fort Worth Texas "Metroplex" (I call it the Metro-mess) of 7.5 million people and growing steadily every single day with a few hundred families moving in _every single day. _ Even with all the engine shops and machine shops there and within 100 miles of there, there is a grand total of 3 and only 3 shops that even have a Pontiac torque plate at all. If your shop tries to tell you that "Pontiacs don't need one" - dump them.
> 
> I ended up buying a torque plate for myself just to open up some options for having work done, and even then it took weeks to get it. I had to wait for the supplier to MAKE it because there's so little demand for them now. They aren't cheap.
> 
> Bear


I thought I was the only enthusiast who got the silly notion of buying his own Pontiac torque plate.


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## Fxnjetz56 (Mar 21, 2015)

BearGFR said:


> That item that Jim mentioned, "4.) Bore/Hone .020 (torque plate) " is super important and make sure that you "grill" the machinist about it. I live very close to the Dallas/Fort Worth Texas "Metroplex" (I call it the Metro-mess) of 7.5 million people and growing steadily every single day with a few hundred families moving in _every single day. _ Even with all the engine shops and machine shops there and within 100 miles of there, there is a grand total of 3 and only 3 shops that even have a Pontiac torque plate at all. If your shop tries to tell you that "Pontiacs don't need one" - dump them.
> 
> I ended up buying a torque plate for myself just to open up some options for having work done, and even then it took weeks to get it. I had to wait for the supplier to MAKE it because there's so little demand for them now. They aren't cheap.
> 
> Bear


Thank You for the input. My experience thus far closely tracks yours...and yes, I’ve looked at torque plates myself ($300-$600).

In addition, I live in the Chicago area...you’d think a Mecca for machining services, no longer. At least not so much for automotive...less for Pontiac “specific” . I have one Pontiac restoration shop near me, I’ve inquired about his engine builder. I talked to them directly and its a 6 month turnaround...5-6k for a stock rebuild, no dyno services.

I’ve visited a performance race shop that builds a variety of engines, almost all high performance, literally 15 minutes from my house...PERFECT!...but no. I spent 45 minutes with the owner, I showed him an engine “recipe” from someone we both know (I think). The guy spent 20 minutes telling me that most of the stuff on the page was obsolete junk, insisted I needed (wanted) a roller cam, and seeemed truly perplexed that anyone would pay good money to lower compression. He’s a 10:1 cast iron/11:1 aluminum head guy. Also thinks a set of forged I beam rods are a waste of money...he’d rather check and recondition my 50 year old set. Which, I suppose a valid argument could be made for either of those options...to me, the delta in cost for me...makes a new forged set a no brainer.

Anyway, long story short, I asked him to quote me on an engine he WOULD build, using my intended usage as a guide (street/performance). During the visit, his verbal self said we were looking at something approaching $6500.00 all in...dyno’d/broke in/tuned/painted. His formal on paper quote...$9300.00. This for his roller cammed, 10:1 motor. He does though, have and use torque plates...!

Ive widened my search area. Highly rated shop in Wisconsin...looked like a good prospect, lots of racing pedigree, does a fair amount of Pontiac stuff. He’s 6 months behind, said he might entertain doing my machine work...no promises on even turning that around...I’m supposed to call him back next week to see if he can squeeze me in...so, not happening.

Another highly rated rebuilder up North (6 hours away) happy to take me on, they do some Pontiac motors...but only up to long block. They have complete services, and high end dyno....for Chevy stuff...again, prolly a no.

I reached out to another legendary/reputable Pontiac guy in Oklahoma...really great conversation, more than happy to take on my engine. He has no cores, so no pre built stuff in stock, or in process. He will do my engine, maybe 3-4 months turn time (did I say I’m not in a particular hurry? I’m not). So this seems like my current path to a motor.

But wait, there’s more...He has a different “recipe”. So, that’s the rabbit hole I’m in now. He uses his basic lowered compression 400, with the usual standard machining operations. 
The twist...he recommends a Melling 041 cam (SPC 8 I think), with Rhodes lifters, and 2000/2200 stall. Forged pistons, recondition my rods etc. prolly end up around 6k All in.

This seems a reliable recipe, maybe a bit dated, but would certainly fit my intended use (and budget). I think I’m spending too much time in the forums...ask 5 people...get 10 different opinions, which, don’t get me wrong...I’m happy for the input and advice, It is difficult though to reconcile all the opinions into one distilled clear path to a slightly updated 400 motor.

I’ve read a lot of Cliff’s stuff, this recipe seems to track some of his thoughts cam/lifter wise...I think though he’s at higher compression numbers. And if I parse some of the work he’s done...he’s moved on to a somewhat different recipe...not sure what exactly...I need to do some more digging.

Anyway, thanks for weighing in Bear...I remember following your build way back...I’m still catching up...


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## deanhickey (Apr 6, 2015)

Been down that rabbit hole myself, Just had my 400 stroked to 4.25 for approximately 466ish CI, lower the compression to the 9.5 some by using 22cc dished piston and went with the 068 cam. very happy with the engine ,purrs like a kitten and great street manners but can still break traction going thru the gears (automatic). running 3.36:1 rear end and a stock q-jet. had all the work done for 5k. pull and install done by myself. Good luck and don't get overwhelmed.


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## Old Man Taylor (May 9, 2011)

Personally I would only use the 041 with Rhoads lifters if you use a stroker crank. Jim Hand was the big proponent of this combo, but he was running a 455. I drove his wagon and it was very impressive. However, I don’t believe it was his daily driver.


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## michaelfind (Dec 14, 2018)

Old Man Taylor said:


> Personally I would only use the 041 with Rhoads lifters if you use a stroker crank. Jim Hand was the big proponent of this combo, but he was running a 455. I drove his wagon and it was very impressive. However, I don’t believe it was his daily driver.


OMT, I'm always impressed with how you know everyone who's anyone in Pontiac history. Now, I learn you even drove Jim Hand's car. Wow! I paid dearly just to get a used copy of his out of print book. I am in awe.


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## Old Man Taylor (May 9, 2011)

I make it a point to try to meet people like this. I was at a convention in St. Louis, so I took excursions to meet Jim Hand and Jon Hardgrove (The Carburetor Shop). The one holding the carburetor is Jon Hardgrove. The one inside the station wagon is me, outside is Jim Hand.

Jim wanted me to drive the wagon to see how smooth the transitions were with the Cliff Ruggles built Q-Jet. He said, "just roll into it", so I did. I rolled all the way into full throttle. Finally he said "I think that's enough". Follow my Tempest racecar story as I will be posting a few more like this.


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## Old Man Taylor (May 9, 2011)

I cropped the picture with me in the car so you could see it for sure.


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## Old Man Taylor (May 9, 2011)

Since I'm on that topic, here's a few pictures of Jon's shop, which is at his house. He actually owns the Stromberg business. He's in Eldon, MO and Jim is in Lees Summit, MO. That's right out side of Kansas City.


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## PontiacJim (Dec 29, 2012)

Fxnjetz56 said:


> Awesome Sir, thank you for your time and attention to detail. Not like I'm unfamiliar with going down a rabbit hole now and again...but this...is a rabbit hole within a rabbit hole...inside another. Ive been scouring the forums, and have found so many different opinions on what works. I am beginning to at least identify some common denominators between all the varying opinions...Detail like yours surely helps. Thank You!


Yes, if you ask 10 people how to build an engine, you will get 20 recipes. You are not alone as this comes across here enough and the more you research and ask questions the more confused you will become and then you will second guess yourself and others and get further confused.

When you ask such an open question, the answers are based on the HP/TQ each person "thinks" is the right amount. One guy might feel best with a stock 360HP build while another guy will tell you the only way to go is a stroker engine, KRE heads pulling 330CFM's, and pushing 550HP/TQ. So any replay you get will be a reflection of what a builder or owner feels is best - but may not be best for you.

That is why you have to dial in an expectation for what you want out of the car and engine. You can't have it all. Do you want street, street/strip, race? Do you have a budget or a wallet that is bottomless? Are you willing to upgrade your drivetrain to handle the extra power/torque or keep what you have? Do you want to run pump gas or race gas?

ALL of these factors come into play and you have to know what you want and then have a range that can be worked with. There are plenty of arm chair engine builders when it is not yours, so don't get sucked in. Then there are those who are engine building engineers who can throw flow numbers, cam specs, valve spring pressures, and how to hog out your heads. All fine and good, BUT, does this apply to your build? AND, if you leave out just 1 item from their recipe, will your engine still do the same?

The factory 360HP 400CI was plenty enough to smoke tires, throw you sideways, and chirp gears while getting 14 MPG's. How much more do you need? More HP/TQ to smoke tires faster and further? MPG's down in the 10's? Is it really that embarrassing that you can only get your car down into the high 13 second 1/4 mile when most seem to claim they can do 10's? Who you gonna street race today, and where? A good solid 400-425HP is doable, but you really build a Pontiac for torque, not HP. That is the difference of the Pontiac versus other makes, torque down low that really pulls hard if you can get the traction to use it.

Don't get me wrong, I like HP and smoking off tires, sure 500-600HP would be fun, but I probably could not afford the gas needed and the gas mileage would kill me, so I might get to drive it 2 or 3 times a year. So ho much fun would that be? But that's my financial standings, while another may have no issue burning up $130.00 on a Friday night every weekend.

So going exotic on a Pontiac build is only putting more $dollars in someone's pocket that may not be needed and puts you more into a street racer than a nice cruising car that kick's butt. It is fine to do a lot of reading, researching, and comparing, but use it as a guide to decide what YOU want out of YOUR car/engine and how much $money do you care to spend. Sounds like you have hit a couple reasonable engine builder, and some not so reasonable. So keep researching and asking questions.


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## Fxnjetz56 (Mar 21, 2015)

PontiacJim said:


> Yes, if you ask 10 people how to build an engine, you will get 20 recipes. You are not alone as this comes across here enough and the more you research and ask questions the more confused you will become and then you will second guess yourself and others and get further confused.
> 
> When you ask such an open question, the answers are based on the HP/TQ each person "thinks" is the right amount. One guy might feel best with a stock 360HP build while another guy will tell you the only way to go is a stroker engine, KRE heads pulling 330CFM's, and pushing 550HP/TQ. So any replay you get will be a reflection of what a builder or owner feels is best - but may not be best for you.
> 
> ...


Thanks Jim,

All good info. So maybe got lost in the shuffle between posts, but I have (or had) a pretty clear goal from the outset.

I have a tired, worn out 400 in my 67 GTO. I’ve had the car for 10 years, and fairly recently, could detect the slightest rod knock at idle. The ever persistent slight rear main oil leak, was becoming...well, more persistent.

The engine compartment/front suspension also well ready for a rebuild/restoration.

Though I’d never heard the motor ping or knock, I’d been told that with 670 heads, this motor was boderline on tolerating pump gas. On tear down, I discovered that all the upper connecting rod bearings badly worn and all in copper. I’ve been told, thats a sure indication that detonation was occurring, audible or not.

Anyway, my goal was, and still is pretty simple and straightforward. Rebuild the motor to a lower compression, pump gas friendly unit. Spend some money on some higher quality essentials...mainly forged pistons/rods. Choose a cam somewhere in the vicinity of an 068. End of day, take a motor (YS code) that was rated at 335hp, and cajole it into a more 360hp version that will be happy on today’s gas...that’s it. Game/set/match.

In addition to the above core principles, and complimentary to my goal, my thought was to lose the original exhaust manifolds, and update to ram air exhaust manifolds with 2 1/2” pipes. On the intake side, I’d like to swap out the performer intake/Holley street demon carb, and return to a stock cast iron/Quadrajet.

The ballpark budget I had in mind was something in the neighborhood of 6k. I have really no target hp/tq numbers I need or want to hit. 

I’ve gotten 3 possible recipes from Pontiac builders to date. They all revolve around this basic formula in terms of necessary machining, lowering compression, and adding the forged bits. None of these contemplate going with a stroker. None even contemplate zero decking.

3 variations then to date:

Comp cams XE262H

Comp cams XE274H with a 2000-2200 stall

Melling 041 pattern (SPC 8 I think) Rhoads lifters and a 2000-2200 stall

The local performance engine builder, sent me a 9k+ quote for a 10:1, roller cam motor, which I’ve rejected. He’d spent the first 20 minutes telling me why I’d only want a roller setup, and why he never had anyone spend good money lowering compression...so...not a good fit for me.

Hope this helps explain my basic goal/expectations.

Thank You again for your thoughts...

P


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## Fxnjetz56 (Mar 21, 2015)




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## Old Man Taylor (May 9, 2011)

Measure everything before you order pistons. Then spend some money on the pistons and get the exact reliefs you need to get your compression in the 9.25:1 range. That gives you some margin at little to no performance loss. MAKE SURE that the reliefs are not under the head surface. That's the quench surface, and it needs to be flat. The picture is of the pistons I had made for my 428. I don't understand that one engine guy saying it needs to be 10:1. Run away.


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## Old Man Taylor (May 9, 2011)

As to your cam ideas, personally I would stay away from the 041, even with the Rhoads. Plus the Rhoads are noisy. With a loud exhaust you don't much care, but they do make a lot of valve train noise. So bad that a friend of mine replaced his with the "quiet" Crane version. They still made noise. In some of my 400 rebuilds, I have used cams much larger than the 041, but they were strictly performance builds. Stick shift, gears, high RPM, etc.


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## Fxnjetz56 (Mar 21, 2015)

Old Man Taylor said:


> As to your cam ideas, personally I would stay away from the 041, even with the Rhoads. Plus the Rhoads are noisy. With a loud exhaust you don't much care, but they do make a lot of valve train noise. So bad that a friend of mine replaced his with the "quiet" Crane version. They still made noise. In some of my 400 rebuilds, I have used cams much larger than the 041, but they were strictly performance builds. Stick shift, gears, high RPM, etc.


OMT,

The 041/Rhoads combo with a stall, is the recommended setup by a well regarded Poncho builder (Somewhere in OK) I had a good conversation with him, he will build whatever motor I want...but he’s really big on the Rhoads lifters.


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## Old Man Taylor (May 9, 2011)

Make sure he’s talking about a 400, and not a 455.


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## Fxnjetz56 (Mar 21, 2015)

Old Man Taylor said:


> Make sure he’s talking about a 400, and not a 455.


Yes...400, he knows...


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## 67ventwindow (Mar 3, 2020)

Thank you for the bearing pictures. I didn't understand the copper reference without that. I never seen bearing like that but I have limited experience. Wish you success with your rebuild. Thank you for sharing.


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## Old Man Taylor (May 9, 2011)

I think you would be happier with an 068 compatible hydraulic roller, but that's just my opinion. The combination of a 3.23 rear and a 400 is why I think that. The key for any cam you decide to use will be the selection of a torque convertor to match the combo.


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## Fxnjetz56 (Mar 21, 2015)

Old Man Taylor said:


> I think you would be happier with an 068 compatible hydraulic roller, but that's just my opinion. The combination of a 3.23 rear and a 400 is why I think that. The key for any cam you decide to use will be the selection of a torque convertor to match the combo.


I’m leaning that way as well...maybe if I was 19 and wanted a noisy clattering beast under the hood I’d go the other way...but I’m not...

Would consider the comp XE262H an 068 derivative...?


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## Old Man Taylor (May 9, 2011)

Yes, I’m just not a proponent of flat tappet cams any more.


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## PontiacJim (Dec 29, 2012)

I like 6K as a target price. That to me sounds within the range of reasonable. 9K in my book is out of the question for a street build.

*OMT* has provided a great picture of what your piston tops should look like. These match the close chambered heads and has that nice flat area to give you a good quench/squish - which you want as this forces the air/fuel mixture into the combustion chamber for a complete burn which also helps fight off detonation.

There is detonation you hear, and detonation you can't hear, but is taking place and damages the bearings which I think you are seeing. Detonation hammer bearings.

You don't want the 041 cam for a 400CI, in my opinion. Way too much duration and cam overlap. You need higher compression to take advantage of this cam and it is not a good choice for under 2,500-3,000 RPM's and then you need a built that will spin upwards nearer 6,500 RPM's to take advantage of it. The Rhodes lifters tame this cam down on the bottom RPM's to make it more street friendly and up vacuum. Much better choice for the 455 or 461 stroker as the bigger cubes by themselves make a bigger cam smaller.

Pontiac heads, in stock form, don't flow much over .450" lift. So you don't need much more than that, but many cams will get into the under .500" lift. But you will increase flow with a good 3-angle valve job, and then add the matching valve springs for the cam's lift. I like the specs on the XE-274 and used it in a 8.2 compression 400. The 262 may be too small and cause detonation due to the intake closing point.


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## Fxnjetz56 (Mar 21, 2015)

PontiacJim said:


> I like 6K as a target price. That to me sounds within the range of reasonable. 9K in my book is out of the question for a street build.
> 
> *OMT* has provided a great picture of what your piston tops should look like. These match the close chambered heads and has that nice flat area to give you a good quench/squish - which you want as this forces the air/fuel mixture into the combustion chamber for a complete burn which also helps fight off detonation.
> 
> ...


great info Jim thank You...Im finding a definite convergence of opinion in terms of cam choice. The 041 in particular seems like a place I dont want to be, at least with a low compression 400. Talking to Len, this is a combo he swears by with the rhodes lifters...tough to argue with someone with his rep, and product. However, I'd rather not be reliant on noisy variable lifters and a converter to make this combo work.


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## Old Man Taylor (May 9, 2011)

Remember, it’s YOUR engine.


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## lust4speed (Jul 5, 2019)

OK, can't let the two guys named Jim have all the fun. My son's '65 2+2 has an 041 cam along with the newest Rhoads lifters. Noise is about like solids. The overlap built into the 041 cam pretty well insures some watery eyes if you are behind the car. We've had several cams in his car, and the 041 gets the job done but even with the Rhoads lifters, mileage dropped 2 MPG from the previous Summit 2802. A few more horses, but not enough to make up for the drop in mileage.

Stock rods suck, and by the time you pay for reconditioning the rods and adding ARP bolts you simply are not saving much money over purchasing a much stronger rod.

The '67 balancer is still the early version and the timing mark is on the cast hub and cannot slip out of adjustment like later balancers with the mark on the outside ring. Personally think it was one of Pontiac's better ideas that they should have retained.

I agree with OMT that there's no reason to go over 9.25:1 compression for the street. Another important thing to consider is the larger the cam the more compression can be run. A cam in the 068 to the mentioned Comp cam isn't big enough to be talking about 10:1 compression. The original 068 cam had an LSA of 114.5° and was really an amazing all around cam that would pull off idle and make nice horsepower at reasonably high RPM. the Comp cam on a 110° LSA is more prone to detonation and will have a slightly choppy idle. Personally I'd go with a Crane or Crower cam with about the same duration at .050" but those two companies put theirs on a 112-114 degree LSA which helps smooth out the idle, have better horsepower down lower in the RPM band, and are less detonation prone.

Reason I don't like flat tappet cams is they have a really bad tendency for the lobes to go flat no matter what the additives or care given to them. My son was on a budget and went with the flat tappet against my advise, but the valve train has lived a good life. Part of the reason is the cam is from Crower and for whatever reason they seem to have less problems, and the other reason is the Rhoads lifters are made from good stuff and survive where other lifters would fail. Ask my son today what he would do and he quickly states that he would go for the piece of mind and would have spent the money for a roller cam and lifters.

Another reason for choosing a roller cam besides longevity is these cams can make more horsepower while retaining a much better idle and road manners at a given duration. Simply put, the valve can wait to open, open quickly, open higher and stay open longer, and then shut quickly. Basically more horsepower without a penalty over the same size flat tappet.

While the graphite rope seal is good and was what I did use, I now go with the BOP one-piece seal. Either one is massively better than the rope seals included in the rebuild kits.

Another vote for the SMI carburetors. Think I've put on four now and they are totally on the money right out of the box.


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