Originally Posted by Adger Smith (Post 707254)

Bob,
Through all the 60 years I've been racing I have always heard the Corvette ratings were higher on like combinations because of the Stock Exhaust manifolds and the Stock Pan configuration. For the life of me I can't see how a Exhaust Manifold difference in all classes that allow aftermarket headers is even a consideration for HP variations. Now a Stocker with a Stocker pan.. I can see that there could be a difference...In Super Stock and Super Stock GT where aftermarket pans are allowed I don't see any reason to add HP to "like" engine combinations. Is NHRA Tech going back to some wheelbase considerations like in the old days with Ford and Mopar??

Originally Posted by Lyn Smith (Post 707029)

DId you ask MR.Cvengos for a explanation?

Originally Posted by Jim Cimarolli (Post 707257)

The 65 Corvette 425 hp 396 is a perfect example. in 66 it was rated at 375 in the Chevelle with a bigger cam!

Originally Posted by Dan Bennett (Post 707286)

Yes, the manifolds were the official explanation but the word I always got was that the real reason was internal politics. There was a time when the suits decided that Corvettes would always have the highest HP outputs. I had 2 L78 Corvettes and one L78 Nova - never saw any difference whatsoever.

Sort of the same thing, but I remember a conversation with retired Chevrolet engineer Paul Pryor at Gainesville one year where I mentioned that the 70 Buick Stage 1 had the highest torque of any of the engines at 510 (the LS6 was 500). He immediately got a bit agitated about the games the different divisions were playing back then.