[jakeshoe]

Your average 454 Chevy after 1975 came with peanut port heads which are probably a smaller runner than a Pontiac...
Most guys at the 500 HP level and less are running the oval ports which are not massive and make a good all around power curve.

Ford FE motors don't have massive ports, etc..

Pontiac motors are generally torquey setups BUT, cube for cube they aren't that much different than any other American pushrod V8.

It's even been proven that a longer stroke doesn't necessaarily create more torque than a larger bore/shorter stroke combo for the same cid...

Anybody that has dyno sheets should break them out and look at comparable builds in other engines, you'll see a trend, a 455 Poncho with a ~230 ish cam, common headers, aftermarket intake, etc, will be pretty close on the dyno sheet to a 454 Chevy, 460 Ford, 455 Buick, etc with similar equipment.
I'm not knocking Poncho motors because I've built a few and they are to me one of the classic icons of American power but you have to "leave the bubble" sometimes.