Anyone reproducing brake backing plates for 8-3/4's or Dana's ??

Doc Diff used to sell the entire setup, might ask him.

https://www.doctordiff.com/mopar-drum-brake-assembly.html

I haven't seen any repros out there. I had been looking for a decent pair of 11x2.5 plates for awhile.
I got lucky and found a newer pair of NOS ones off ebay about 5 months ago.

Are the backing plates 8 3/4 specific? I've been tripping over a set I pulled off a '77 9 1/4 rear months ago.

That's what I get them from, Dodge vans with 9-1/4". If I remember, they have four bolts, but the plates have five holes.

Reading some other posts (some quite old) it seems ALL Mopar diffs can use the same backing plates - 8-1/4, 8-3/4, 9-1/4, 9-3/4 - all interchangeable. HOWEVER, the plates will differ (obviously) between 10" and 11". Not so obviously they also differ depending on the shoe width - a wider shoe will need a plate with more offset from the mounting flange - and this will not be as visibly noticeable as the diameter!

Dr Diff currently (as of Friday) has no backing plates for his kits.

Worth noting is that virtually everything - EXCEPT backing plates - is available from RockAuto, etc.

I have a set of 11" drum setup from an 88 M body on the 8 3/4 in my 65 Cuda (cut down C body axle).

Are there pictures that show the difference in backing plate for the shoe width?

What magazine and issue (year/month) is that article from?

That was in mopar action sometime in the past year or so.