360 vs 383

1. 383. Might be a bit heavier, but keeping everyhting else equal it still has an advantage. "Bigger" heads, slightly bigger cam, more compression and 23 extra cubes. Might be held back by the smaller carburetor vs a T-quad on a 360 but not by much.

For scenario 2, 3 and 4 I would still choose the 383. Stronger block, bigger bore, larger valves. 383 might be more $$$ to swap in an a body due to headers and engine mounts, but other than that I would choose the 383.