Stock Pontiac VS Performer intake

[motorheadmike]

Gasket/port match the heads and Performer intake... both are not going to compliment each other. If you have the means open up and smooth the runners back to the carb flange. This will help you gain velocity to the back of the valve - very important if it is a wet manifold. I did this for the mid-rise intake in our TBSS which has a dual quad lower half. Well worth the time.

Theory:
http://www.tbssowners.com/forums/heads-cam-intake-manifold-internals/147193-other-holley-intake.html

Results:
http://www.tbssowners.com/forums/2814210-post59.html

 

[olds307 and 403]

Well I would not compare the Chevy with any of the BOP motors. The short stroke works against torque and Edelbrock may have targeted upper rpm performance with the Chevy version. BOP owners know that their long stroke torque monsters are perfect for motivating big heavy cars. I'm pretty sure Edelbrock's engineers knew to fit the punishment to the crime.

The long strokes do help and also probably the heavier respricating parts, are also supposed to help torque production. The Olds 350 and 403 do go against that, big bore and short stroke but superior torque production. Don't forget the different valve angle and longer intake runners, which all Olds have over type "C". Long and smallish diameter runners help torque production. Of course too small, think SP2P, help low rpm, part throttle but totally kill top end.

 

[deanlemans81]

I have an old style Performer P4B intake on my 400 and it workds well. I did not use a factory manifold so I can't comment on the before/after but it suits me fine. I have 6x heads, used a felpro intake gasket and I have no issue with the exhaust crossover. One issue I did have however was the bracket for the throttle cable. the bracket changed after the 72 model year and the boses on the manifold reflect that. Just make sure you have the proper bracket for the year manifold. I couldn't find a 72-down bracket at the time so I used and tweaked a universal one.

 

[Bonnewagon]

I remember the P4B. It was a good street manifold that was made back when we had few choices. We mostly used it when we upgraded 2 barrel big car 400 motors. I can't remember the crossover port sizes but my buddy used it on 1971 heads. I am using 6X heads too and the Performer does have the matching crossover ports so that may be the deciding factor. Yes, I did notice the throttle cable mount was different- hopefully I have the right one somewhere. I went to Grainger today and of course my .012" stainless sheet was not in stock even though it was supposed to be. They explained that "in stock" meant "somewhere in the system". In this case- Massachusetts.

 

[pontiac guy]

I saw a dyno test in HPP a long time ago, they did that very comparison. The factory intake performed identical to the performer. The only advantage they could tout was the weight savings.

 

[84GP455]

Wow that's funny that you mention that article on HPP Pontiac Guy, I remember the same article and the same conclusion as you too, I was a long time HPP subscriber and I probably may still have the magazine that it was in. I still have a lot of HPP magazines saved I should try to find that particular article. I also remember the article when they compare the differences between aftermarket headers vs. stock Pontiac manifolds.

 

[pontiac guy]

I don't remember the hedder comparison. Was it the logs or the actual cast factory hedder exhaust manifold that they are repopping now? I used to have a subscription to every car mag available until one day I opened a Hort Rod and the reprinted the exact same article. I mean exact. It had the same effing typos in it. They didn't even bother to reproof it. That was the last subscription I paid to them, after that I slowly started winding them all down. I was buried in back issues. I finally went through and saved the issues that had useful info in them and recycled the rest. it was still a formidable pile, but much more manageable. Of course I have never looked at them since. been in a box for 20 years and 4 states

 

[Bonnewagon]

I too remember those articles. I have almost all the HPP's and even some Thunder Am's. That is why I asked for real world experience with the Perfomer. I have always used the stock manifold just because the aftermarket ones were no better. Not even the factory aluminum jobs. Back in the day we just took it as Gospel that the "RA/HO" stuff just HAD to be better. Well, the exhaust manifolds were lots better, but the intakes were not. As I stated, I may use the Performer just because the crossover ports are a match. I have only one of the H-O Racing stainless steel block-off plates left and I use that to make copies. I have two sets of the '67 long branch exhaust manifolds, both from HO cars. But they only fit my '68 Firebird- not the Bonnewagon- so I am limited to the log exhaust.

 

[deanlemans81]

For manifolds you have to use GTO ones. I have reproduction 67 ramair exhaust manifolds on my lemans from RARE and they were a perfect fit.

 

[pontiac guy]

I like the idea of the factory style exhaust hedders vs the tubulars. I had a cutlass with a Pontiac 400 in it back in the day and the hedders didn't fit right, they cooked my starter etc. Plus, as an old guy I like the look of "factory" performance.

As for the intake, I agree use the Performer. It fits right, you have it and it wont be worse than the factory. Plus you will save a gagillion pounds off the springs.