Weird rear brake noise

If anyone has seen this before and has an answer for you it will be Cass at Doctor diff. Be is very knowledgeable, bonest and fair. I would give him a call.
I actually emailed them and the only thing they could think of after discussing what was going on was possibly the shoes being 2-1/2" wide instead of the 1-3/4" that came on pre 72 models