What kind of compression are you hoping for.
With a 67 cc w2 and a 4.00 crank stock 340 bore and a Ross .100 flat top dome I get 12.7:1 which I am told is just enough for alcohol.
No idea yet but my last 408 that ran low 9.70’s was around 10.5 with flat top pistons and open chamber 340 style Edelbrock heads. I do a fair amount of chamber work on the heads and the decks were never trued up on that one. I’m betting over 13.2 or more easily on this one.