I think this general census has caused people to leave power on the table, yet to see dyno results that prove 318 heads make more torque down low, not saying velocity isn't important but we only have a few head choices and yet seen a dyno result that shows one killing low end torque.
Yah, yah. I got that. OP mentioned keeping small ports. For a low RPM street engine, keeping port volume down keeps velocity up. You want a race car, go play on a racer forum.
Now a little judiscious porting can aid flow and power, as I was describing. Air speed with the flow going where it wants to go can be aided. You need the velocity to generate the swirl.