B Body Mopar B Body Mopar forum

Backing plate and drum interchange

63hemipolara
08-26-2008, 11:24 AM
I was wondering if the backing plates and brake hardware are interchangeable between any 8 3/4 diff. I have a pressed in axle diff from 63 with a 741 case and I want to change it for a more modern 68-70 b-body 8 3/4 with a 489 case.

Can I swap my brake hardware. Anything one should look for when checking out used pigs from these diffs other than chipped gears and the correct wear pattern on the gears? Thanks group.

69 Runner
08-26-2008, 02:17 PM
Sounds like you've got the used pig covered. When it gets right down to it, the only way to really know what you've got is to 1) buy new (or rebuild) or 2) run it.

I've never taken a caster nut type 8.75 apart so I don't know for sure. But my guess is as long as the plates have the holes to bolt down the axle plate, then they will swap

Big Mike
08-27-2008, 01:16 PM
I don't have an answer to your question but i know that the only rear that will bolt right up to your '63 and not have the tapered axles is a '65.
Thats what i'm using.
I Picked up a banjo rear from a '65 plymouth and it bolts right up.
The '68-'70 is wider. I'm not sure if the rear itself that is wider or just the perches. Either way it would have to be modified.

You can run either a 489 or 742 case with a '65 rear also:beerchug: