I had shaking issues on my '64 880, too, and they were tire and brake related, but not like you described. Basically, people put the cheapest shoes on their car, and wonder why it won't stop. I had just the fronts relined at a local brake and clutch supply shop, told them I wanted the good stuff, and they worked great. Cost $60. Back were stuck like yours. I tried slide hammers, I tried "The Knocker," which is a chunk of metal you screw onto the axle shaft and hit with a sledge, and nothing worked. This did: http://www.chrysler300club.com/rcmstuff/fairbanks/puller.html I welded left and right hand lug nuts together for the left side. Then I did this to convert to slip on drums. I drilled the center of the lugs almost all the way out to the knurls so the drum wasn't damaged: http://hotrodsandhemis.com/TaperedAxleBrakes.html Drums are located by the center register, not the lug studs. For disc brakes, Scarebird had a kit that used cheap, readily available parts, but they've shut down since Covid, and I don't know if they'll start up again, so relining your shoes may be the most cost effective way to go for now.