Why? You did exactly what it took to run 10’s if you’re going to stick with a 15” rim. I suppose the purists might give you some grief for the bodywork but that’s their problem.
Post factually incorrect information, get a red X. If you don’t like red X’s, stop posting bad information.
Well? I posted how it’s done. Simple fact is that there are more than a few A-bodies that have or can run 18x10’s up front, and some have done so on street going cars.
On a Dart it actually might be less work to run 18x10’s on the front than the back, although both can be done with the right parts and some minor modifications. Although in the back to really make use of the 10” rim it would be better to do a 3” relocation and mini-tub.