CLASS RACER FORUM - How many 9 second 396/375 alum head A/S A/SA

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Re: How many 9 second 396/375 alum head A/S A/SA

Quote:

Originally Posted by Cdncarnut (Post 453556)

This is where things get a bit confusing for a newbie like me.

So, the NHRA allows someone to run an engine combination which was not available for that model year, yet I cannot run a cowl induction hood for the 350/255 combo because the engine option was cancelled before the cowl hood was released?

After checking the classification guide, I noticed that aluminum heads are also legal for the '69 iron block 427, even though that was never offered from the factory.

See my post above.

The GMPP 401 aluminum head is listed as an NHRA accepted replacement part for the early cast iron big block Chevy closed chamber rectangle port head. There is a HP penalty for using the aluminum replacement head. For example, we used them on a 69 Camaro 427/425, and that raised the HP rating from 425 to 435, so we had to add 80 pounds when running them in A/SA.

There are certain parts allowed by NHRA as replacements for old castings that are both difficult to find, and expensive to buy. In the case of cylinder heads, a HP penalty is applied, it usually starts at 10HP.

In the case of the 401 head, it is not allowing a different engine combination, it is allowing the 401 head to be used as a replacement for the OE head, with a HP penalty applied.

The same applies to some heads for other makes. An aluminum replacement head is allowed for certain combinations, and it carries a HP penalty.

Re: How many 9 second 396/375 alum head A/S A/SA

Thank you for the clarification.

Re: How many 9 second 396/375 alum head A/S A/SA

Ken you have a very good car, but a 70 Nova should be 402/ 395 iron, or 402/ 405 aluminum.

Re: How many 9 second 396/375 alum head A/S A/SA

Quote:

Originally Posted by Larry Hill (Post 453573)

Ken you have a very good car, but a 70 Nova should be 402/ 395 iron, or 402/ 405 aluminum.

Hi Larry, You are correct. I have both combinations

Ken Keir

Re: How many 9 second 396/375 alum head A/S A/SA

Quote:

Originally Posted by Ken Keir (Post 453581)

Hi Larry, You are correct. I have both combinations

Ken Keir

And that car looks great doing it---- with either combination !

Re: How many 9 second 396/375 alum head A/S A/SA

Definatley some very fast 396's out there!!

I think A/S will be cool this year too!

Hopefully with the new cars in there own classes it should bring back some old school cars. .

Re: How many 9 second 396/375 alum head A/S A/SA

I went 9.95 in Dan Fletchers car with that combo in the semis in Pomona a few years ago. Unfortunately it was heads up and Jimmy DeFrank went 9.74. It was a 375 h.p. rating at the time but I'm sure Jimmy can still go 9's .

Re: How many 9 second 396/375 alum head A/S A/SA

I think Jimmy, Joe, and Lance can all go 9's in B/SA.

Re: How many 9 second 396/375 alum head A/S A/SA

well if the cars are built with NHRA specs, I would be surprised any of them could

Re: How many 9 second 396/375 alum head A/S A/SA

Quote:

Originally Posted by Doug McCue (Post 453794)

well if the cars are built with NHRA specs, I would be surprised any of them could

You do realize these cars go through an NHRA teardown and I can assure you Jimmy D's is to NHRA spec from that perspective.

TP