[Formulajones]

Originally Posted by Cliff R

+2

A big block Chevy build can get there with a much smaller cam for sure. Less stroke/piston speed, not nearly the mass of spinning and reciprocating parts, smaller bearing diameter, better bore to stroke ratio, and you can drop a tennis ball thru the intake ports on most of the heads they are using to get the big numbers we see on dyno runs, etc.

...

Yes, as comparison, my 454 with a conventional AFR head uses a much smaller camshaft than the OP (242 @ .050) and makes 608hp, and did that with a dual plane intake no less. You just aren't going to get there with a 455 Pontiac using a conventional head and that size cam. Either the cam is going to need to be much more radical or you need a bigger head.

Torque curves however are a different story. My 454 only makes 589 where as a similar sized Pontiac will generally make well over 600 and be nice and flat. But that's to be expected when building a 455 Pontiac that has SBC sized intake ports.