Mushy brakes 4 life...

Mopar92 said

This is the groove where the backing plate goes in that’s rubbing down in the bottom of the groove. Sure the green bearings didn’t narrow my axle flange to axle flange too much and have a major issue there. Ugh.

Red line is where the backing plate rubs.

View attachment 1715138524

Click to expand...

Something definitely wrong with that drum/backing plate combo. If everything with the 8 3/4 is B body then you shouldn’t have any issues like what you’ve got.

So, the next deal is to look at the backing plates. The thing is that there are 3 different 11” backing plates. The plates for the 11x2.5”, 11x2”, and 11x3” rear drums all have a different backing plate offset. They all use the same axle flange offset, so, the plates have to be different. You can’t use 11x2” plates with 11x2.5” shoes and drums, or any other combination of parts.

Here’s a post on how to measure them and what the measurements are for each one. Ignore the title, it has all the BBP measurements you need too.
Converting rear drum brakes from SBP to BBP