GM 12 Bolt wheel cylinders, drums and brake squeak

[cmstillwell67]

Hey everyone,
I have a 1985 K10 and some of the drivetrain has been swapped out.  The rear end is a 12 bolt with Gov-lock. The brakes were squeaking so I replaced the pads up front, new shoes and all new hardware in the rear. I used good premium parts (but they were not wagner)  Its still squeaking.  So I replaced the guide bolts and bushings and greased them on the front.  it only happens at light to medium pedal  when I'm letting off of the brakes.  Now I'm pretty positive its from the rear.  The person before me removed the parking brake cables so I adjusted the shoes until I couldn't turn the drums and then backed them off a little.  I guess I will try replacing the drums now and see if that helps.  The ones that are on it are the 13 inch and I cant seem to find good descriptions on the ones online so will these work?  http://www.ebay.com/itm/400446016526      Also I want to replace the wheel cylinders while I'm there and I'm having a tough time finding the right ones for this rear end with the 13" drum size.  So if anyone could send me a part number I would appreciate it.  Thanks!!

[Captkaos]

Someone swapped in that 12bolt as an 85 would have a 10 bolt.
The only rear ends that have 13" brakes are the JB7 and JB8 brakes on a 14bolt full float.

10 or 12bolts had either 11.15"x2.75 for the JB5 or 11.15"x2" for the JB3.