[James L Miller]

Now that it's settled, "back to the studio" as Jeremy Clarkson might say.

To summarize, if you can get an aftermarket/HP block for your combo, buy one.

If they don't make one for your combo, either run what you can get or buy a foundry and cast your own and then get it approved by NHRA.

I submitted a 318 piston from Silvolite a couple of years ago to NHRA and never heard anything one way or the other. Good luck getting something approved.