Will an 8 3/4 rear end fit in a 73 dart sport?
If you end up swapping out the 9”, an early b-body is the perfect width for the Dart Sport, in my opinion. Before and after pics. In the end, I personally spent WAY too much money rebuilding the “cheap” b-body rear I found. I’d stick with the 9” if I were you, unless you can’t figure out the mechanical issues. Good luck!