Making power out of the 318

People keep on saying port volume of a 340/360 head is too much for a 273/318 (velocity) but is that based on any real world evidence or just assumptions? Or peoples poorly tuned engines and or combos blaming the head or cam or etc..

You build a 350 hp 273 vs 318 vs 360 with the same head there all gonna be at different peak rpm I bet the velocity will be similar.
Friend of mine raced dirt track, ran a 318 with 340 heads. Fastest car on the track.