Radiators in an A-body?
The frame rail spacing is the same on a 72 as the 73+. The difference is if the car was optioned for a 26" radiator it had a larger opening. To answer your question it will fit your 72 but some of the radiator will be covered by the narrow radiator support panels. I think you would still be ahead of the game but on my car I swapped out the radiator support to a 26" one from a donor car.