The OP said big block and eliminated all the serious race stuff. He also just asked about combustion chambers, which is sort of odd, when there's other things much more pertinent to making power. The BS comes in about 65cc and when CNC'd about 75, which is about where you want to be with a flat top piston.

AFAIK, none of the common Mopar heads come with semi finished chambers so they can be properly CNC machined, as is SOP with serious stuff, but the BS is probably best suited to this, for the reasons I mentioned.

Would that be what I recommend? No, I have a set of Victors for the engine that's going to the step down from the B-1. That would be my suggestion at present. S/F....Ken M