I swap a 1968 Hemi Roadrunner drive train into a 1969 440 GTX and then again into a 1970 RT Challenger after wrecking the GTX off a trailer going to the races. No real problems that I can remember, I later bought a 1970 Baracuda that had the same swap, 383 car with a 1968 Hemi K member and motor swapped into it