Correct me if I am wrong, but all the cutting to the core support to fit any larger radiator is all well and fine, but you are still limited to the small hole the M715 has in the front anyway, right? Only a certain amount of air can find its way in that opening. That is unless you swap out a later 70's J truck grille, and core support as suggested above. Then you'd kinda lose the M715 distinctivness.