71 and 72 are close, but not a true fit. The 72 grill curves back on the outside edge. The 72 radiator support has cutouts to accept them. Check it out at
www.texas442.com under Miscellanies.
But, yes, all 71 grills are the same size/shape and interchangable. The only difference is the appearance and color of the grill slats.
C.J.