Auto-X / Roadrace rear suspension 1969 Valiant
The DSE kit is universal, so GM or any brand does not apply. Since the architecture of the frame rails/dimensions of all the muscle era cars are all pretty close, adapting among platforms is not difficult. Of course, everyone wants 100% bolt in......
Personally, I would be inclined to do the DSE kit on my Dart and make it more of a bolt in to potentially make a product for sale.