Mopar 8 3/4 or Ford 9?

Riddler the majority of Ford bolt patterns is the same 5 on 4.5 that Mopar is so there's no need to try to adapt Mopar axles to a Ford rearend. If you want to stay with a 8-3.4 your best bet is to find a complete C-body rearend and have it cut down to the size you need. That way you have all the brake stuff with it. C-body rears go pretty cheap usually.