Cragars on a 1972 Swinger

So I went and checked them out and they looked gorgeous and he even came down a little on price. All was right with the world until... the rears didn't fit. The offset was no good on the back rims and the tires stuck out a good inch beyond the edge of the quarter panel. Very upsetting. Is it possible the track width on a 7.25 rear end 72 Dart is different than that on an 8.75 rear end 71 Dart? He has pictures with the wheels on his car and they look to fit just fine. Anyways, the search continues...