Oh, I was wondering what you were getting at. I prefer not to assume.

I've had my hands on a few 364 cubic inch builds that use cylinder heads w/ 3.1 in2 cross sections. W/ the correct cam they will outrun many 500" builds here at higher weight w/ PS and AC. Btw, the McFarland form misses the mark here as well.

My take...for general street use/grassroots bracket stuff...
Engine performance is dependent on airflow
Intake tract and valve timing/ramps dictate airflow into the cylinder
Assuming similar frequencies, you can use small ports and hang the valve open a long time to get 'x' airflow into the cylinder...or you can use larger ports coupled w/ opening the valve for lesser time to achieve the same 'x'
Smaller ports ultimately limit performance as airflow requirements increase (owner wanting more power). The larger ports allow nothing more than a cam to be swapped for desired results. Ideal camshafts will look quite different depending on head choice...don't expect to run an OTS cam w/ MW heads on a 440 and get exceptional results.

I'm disappointed to see no one talking about how influential the cam is in dictating power/torque peaks. An engine is much more than displacement and heads.