They are the same. I had a 7.25 in my duster when I bought it. I installed a factory hemi car Dana and moved all the rear brakes over and everything fit perfectly.
Not all 7 1/4 backing plates will work. I have a 75 Dart in the shop right now with a SBP 7.25 and they are different.
I think the newer 7 1/4 BBP backing plates are the same but many of the early 7.25s have a 4 bolt pattern that's different than the five hole pattern (you can't just drill a hole). Also, the offset difference that's a problem on the SBP 8 3/4 A body rear may be an issue on early 7.25s as well.
I have a correct set on Ebay:
http://www.ebay.com/itm/33096658105...X:IT&_trksid=p3984.m1558.l2649#ht_3229wt_1119
