Merry Christmas from NHRA HP adjuster

[Terry Cain]

I see on the hp adjustments they changed the hp rating on a 68 Corvette 327/325 motor. That's a mistake. They never made that combination in the Corvette. Are they talking the 327/350 stick only combo?

[Dave Casey]

Originally Posted by Terry Cain

I see on the hp adjustments they changed the hp rating on a 68 Corvette 327/325 motor. That's a mistake. They never made that combination in the Corvette. Are they talking the 327/350 stick only combo?

They lowered the 325 hp motor in the Chevelle and Nova, so I would guess that you are correct. In the Corvette the 350hp/327 motor is the same as the other 2 bodys I believe. They just rated it at 350 because it is in the corvette.

[Bob Gullett]

Originally Posted by Terry Cain

I see on the hp adjustments they changed the hp rating on a 68 Corvette 327/325 motor. That's a mistake. They never made that combination in the Corvette. Are they talking the 327/350 stick only combo?

Dave is correct. Looking at the blueprint specs on the 327/350 in the Corvette and comparing it to the Nova/Chevelle 327/325 motor it appears they are identical Just the Corvette was rated higher for what ever reason. And yes it is a stick only motor.

[Adger Smith]

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??

[Jim Cimarolli]

Originally Posted by Adger Smith

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??

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

[Dan Bennett]

Originally Posted by Jim Cimarolli

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

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.

[Mark Madison]

Originally Posted by Dan Bennett

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.

If manifolds are the issue for this combo and no one uses a stock manifold in stock eliminator with the exception of Gary Hampton, what?s the difference between the corvette and chevelle package?

[GTX JOHN]

Different body and different wheelbase.

My 360 Aspen wagon(112WB) used to be 19 HP more than the
same 360 combo in a sedan(108WB). About 12/15 years ago.
289 vs 270 (Small lift cam 360)

Now they are finally the same HP(289) last number of years after I quit trying
to compete with them and installed a 318.