needing 400 or 450 rwhp for my 67 lemans - Pontiac GTO Forum
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post #1 of 8 (permalink) Old 05-31-2010, 02:01 PM Thread Starter
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needing 400 or 450 rwhp for my 67 lemans

Hello all. I have many questions that will be forthcoming for the 1967 Lemans I'm working on.

But the main thing now is....doing whatever is necessary (within reason) to get 400 to 450 minimum HP out of the car.

My lemans is an all original, bone stock 70K mile car in superb condition (326 V8). I am fairly certain the 326 is not capable of this kind of power (while maintaining reliability) without extensive modification. I prefer to yank the original motor and shelf it for future sale with car at a later date.

I am not opposed to Supercharging (in fact I want to Supercharge). I am not opposed to going to a 400ci or 455ci motor either - or doing both (supercharging bigger displacement motor)...I am opting NOT to go the LS engine coversion route and will instead stay with Pontiac motor/trans combo for originality sake and ease of installation.

I am asking for ya'lls input on the quickest route to get sufficient power - but by still using Pontiac engines.

A fairly wide open question with many many variables i know, but i simply am asking for input from those of you in the know. Which pontiac engines are the best foundation for what i am trying to accomplish?

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post #2 of 8 (permalink) Old 05-31-2010, 07:10 PM
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One easy answer......Butler Performance.........450 hp is the BOTTOM of the scale 2,000 tops........get your finances in order.....
Butler Performance - Popular Pontiac Engine Combinations / Pontiac Stroker Engines

1967 GTO; Gulf Turquoise on Black, 4 speed, buckets SOLD
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post #3 of 8 (permalink) Old 05-31-2010, 09:52 PM
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Butler is the best place if your pockets are deep enough. 500 ft lbs of torque is easilly attainable, still feel fast, but will idle and run an AC system. My buddy says are you building street or strip, because you can't have both.. 455 is the best way to go. But you will have to upgrade your trans, converter and rear end to optimize the combo.

Burning rubber since 1982!!
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post #4 of 8 (permalink) Old 05-31-2010, 09:53 PM
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I got my 383 from Chevy Crate Engines, Chevy Performance Engines, GM Performance Engines, 350,502 Big Block, Muscle Car Engines

I know it's not a poncho, but it's 460hp. I think they do Pontiac motors as well.

They were great to deal with and I was happy with the motor, can't wait to drive it more than just on my street when I get it back from paint.

71 LeMans Sport (72 gto front end)
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post #5 of 8 (permalink) Old 05-31-2010, 10:05 PM
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Originally Posted by jetstang View Post
455 is the best way to go.

If you can't find a 455 go with a 421 or 428, they have 3.25" 4-bolt mains. A 68-71 Ram Air 400 will have 4-bolt mains but, will be harder to find.


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post #6 of 8 (permalink) Old 06-01-2010, 01:04 AM
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700hp Butler engine will run easily on 92 octane. It isnt a cruiser engine it is nasty, but they can make a 500-600hp engine with plenty of grunt on the bottom for street driving. Usually for less than $7k you can get a very reliable and powerful engine from them.

Here it is running doing a half throttle burnout. Its more than enough power for ya, I am sure.

Also if you have E85 available in your area you can crank up the compression and make lots of power, your engine will last longer, idle better and have more mid range and bottom end power. I have two 455s running on ethanol right now, they are monsters. This one will go on it as soon as I get the 1050 Holley converted.

KRE, Kens Speed and Machine, Paul Spotts, and a bunch of others can make silly power too, but Butlers are plain awesome. They have great customer service and will talk with you as long as needed to figure out what you need to get what you want. Jim and David are good people, Jim and I talked for a couple hours at the shop one afternoon. Stand up guy for certain.
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post #7 of 8 (permalink) Old 06-01-2010, 12:06 PM
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LS2 w/ L92s and a decent cam (see bottom of post 7). 450 EASY, plus better drivability and mpg's. they may not 'technicaly' be pontiacs, but at least they put them in GTOs.
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post #8 of 8 (permalink) Old 06-02-2010, 12:17 AM
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I've got a '67 Lemans w/a '67 GTO 400ci (4-speed) that had a rear main seal leak. So among other things (ie paint, ps, pb) I am having several upgrades that are expected to push it near 450 hp. I should know sometime this weekend or early next week once the engine is reinstalled and the car is tested.
Work being done includes: roller cam, lifters, rocker arms, bearings, rings, pistons, springs, bore, balance etc.
Hope this helps.
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