Aftermarket/Replacement Cylinder Head Rule Change

Originally Posted by PJ305

Has anyone contacted NHRA and have them explain how the SBC heads they approved are going to maintain the same runner volumes as the stock head they replace!

It’s up to the racer/engine builder. Not NHRA how that is accomplished. No different that the way it is done now with OEM heads and replacement heads. The NHRA night allow the bigger head and volume the way it is. It’s happened for some of the heads approved now.