B body rear axle in an A body

@Dartnut @ir3333
A good fit on my Duster with whatever unidentified B body rear axle it has was a 15x8 with 5.5" backspace. I am running 255/60R15 but I could probably get a 275 on it using the same rims.
189871948130848846

I have a 68-70 B-body housing and 489 I would like to build for my Duster. Currently it has a 8.25".

I would like to run a 15x8 Rallye wheel. They only come in 4.5" backspace. I have the wheel lip trimmed and plan on getting Doctor Diffs 1/2" spring relocation. Wil that wheel work with a 68-70 B-body rear in a Duster?