Rear

Cuda620,
Maybe I mis understood. I was under the impression you were looking to go from a 7 1/4 to an 8 3/4 and had a b body rear handy. If you have an 8 3/4 and are looking to go up to the 5 on 4.5" bolt pattern just do the axle swap. I just did mine with Dr. Diff axles. But you must use the brake backing plates from a big bolt pattern 8 3/4. I used ones from an E body rear and now have 11 x 2.5" brakes up from 10". I run stock Mopar steel rims with E 60 14" and had no interference issues at all. Thats on my early A 64 Valiant.