Rear CPP disc brake question

[Jarwood]

Let me start off from the beginning.
I have a 72 GMC shortbed. I bought the big brake set up from CPP. Once I got everything installed, I took the truck for a test drive. I noticed the driver side rear had a bad wobble. I didn't think much about it and drove it about 5 miles. I started hearing a rubbing sound. Realized it was my brake pads rubbing against the rotor because of the wobble. When I was installing the brakes I noticed that the brake line to the driver rear had been smashed together...maybe because of the bent shaft????
I bought new shafts and installed them. When I did. the rear driver side caliper was very hard to open enough to get back on the rotor. Finally got it back on and drove it. About 2-3 miles into the drive I started hearing the same rubbing noise. It looks like the caliper is not opening enough to give clearance on the rotor.
How can I fix this?