Re: Best BB heads
4.25 crank might get you most of the way there. Your heads, manifold, cam and carb are on the big side for a 454. That cam is a roller, right? I don't think your heads are limiting factor. your RWHP indicates a little over 500 HP, That seems a little short for the stuff you're running. A 496 would make better use of your existing parts.
Are the heads cleaned up, pocket ported at all? You could get some HP there if they're bone stock.
what kind of A/F ratios did you come up with? Where is your timing?
Tom Terrific or Terrible Tom, depending on the phase of the moon, passing cosmic rays or other factors not fully understood except by my wife.