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

[Cdncarnut]

Originally Posted by TOSTO RACING

It is legal check the stock car classification class guide.

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.