I recall an Engine masters episode and a Richard Holdener video where on a street engine (SBC and Fords) they kept the short block the same and installed different heads with bigger port volumes trying to get the port volume to kill the low end power. As I recall, the low end stayed the same, actually started higher with the bigger heads, about equal at peak tq, and but kept making more power with more and more port volume.
https://m.youtube.com/watch?v=PZSQ5K...dCB2b2x1bWU%3D
What makes a Pontiac different?