Notwithstanding the Boss302, as far as 302's go, the most powerful (carbureted) would most likely be the '85 302-4V HO, roller cam motor with 225hp (net). IIRC correctly, the '84 had a poorly designed head (combustion chamber).
It should also be noted, that if you want more "GO" with the least amount of "MO", consider swapping in a 351W. The hassles would be about the same as going to a late 302, and there is so much more potential, especially torque, which is what you feel in the seat of your pants.
'66 A-code Fastback (therapy)
'89 Town Car (SWMBO D'driver)
'87 Caprice (as req'd by Hagerty)