Have you taken the drums off since this started? It sounds like the springs were installed wrong. I had my rear brake hardware fail on me earlier this year and spent 26hours on the bloody mess before I got it repaired. My drums are WAY out of round but my brakes no longer lock up. Can you imagine 6 hours of cursing, torch, hamering, and dremel grinding just to get ONE drum off? Since I had to do both rear sets multiply that x2. My wife and I have done brakes on Fords, GM's, MG's, Mopars, ect. and never encountered anything remotely the pita this brake job became.