Reality check: A body rear ends

Find an 8 3/4 housing and send it to Moser. They can modify it for A body axles. Aftermarket BBP axles are relatively inexpensive, Or get a set of OEM small bolt axles cheap. Get a Pumpkin, any number will do. Replace seals, get brake assemblies and bolt it in. An A body 8 1/4 should be fine for what you want, if you can find one.