Gains, basically because he beat Carnera, which, in my opinion, puts him above Coffey. Gains also beat the very young Schmeling. I think Gains was probably a much more skilled boxer, although I have not seen Coffey on film. Gains looks impressive on film against Carnera.
Gains takes it he was a fine boxer with respectable power a good chin and too much of everthing for Coffey,imo
Gains in a cakewalk. Coffey was just a big strong kid with few skills and a suspect chin. The Canadian boxes his ears off in the early go then puts him down and out in the sixth or seventh round.