Weird front brake noise after new shoes

[Rust-O-Matic]

I just replaced the wheel cylinders, shoes, hardware, springs, self adjusters, wheel seals, and repacked the bearings on the front of my '66 C20. The two flat head screws in the original (presumably) drums are permanently frozen in place, so I pulled the whole hub to get it off. The driver side turned out great, but the passenger side makes a loud, repetitive, echoey scraping/chirping noise when I rotate the wheel/drum. Its not smooth either, like something is rubbing. It makes 8 noises per rotation so I assume its something interfering w the back of the wheel studs. I have taken it apart numerous times, adjusted and re-adjusted the castle nut on the spindle/bearing, retracted the shoes all the way in, shifted them side to side, flipped them over, and inspected the springs numerous times to make sure nothing looked like it was sticking out. The wheel seal is completely seated and the backing plate doesnt look warped or bent. It pretty much has to be something touching the studs. I'm about to tear my hair out. Nothing seems to affect the noise.

Has anyone had anything like this happen? Any ideas on what else to check? I think my next plan of attack is to drill the screws out of the drums and bash the hub out of the center so I can put it on seperately and see what's going on without the drum in the way. Had to give up for the day though, and I'm sitting here scratching my head. I intended to attach a pic but its too big and I don't know how to shrink it on my phone.