ford 9 inch really?

Actually a Ferd 9 is quite a bit stronger than an 8 3/4 but that's not why I run one.

Mine is a 78-80 something Linc Versailles. You an throw them right under a Dart there is something like 1/4" wider difference on the spring pads. The Versailles has factory rear discs

It was something "I found" easily and since have acquired another complete one for parts

9" parts are just about the most plentiful on the "traditional" used market you can find "pumpkins" and rear axles on CL almost constantly

They can be MADE stronger by using aftermarket 3rd member parts and axles. The big advantage over a Dana is they are lighter, and if you either want to change gears or break a third member it's an easy job to swap it out