4700 2 Wheel Hydraulic Brake Drag

My 4700 rear brakes were dragging, you could hear them squeaking when first starting the truck and driving. I replaced the calipers, pads, and had the rotors turned. The old calipers were junk the boots were falling apart and the pistons weren't in very good shape. Since then I drove the truck about 80 miles round trip and when I got back I could put my hand on the front rotors and they were cold, the rear rotors were hot and I could put my hand on them but if I left it there for long I would burn myself. I removed the rubber brake hoses from the frame to the rear calipers and can blow through them each way with my mouth. Could the Master Cylinder be keeping the rear brakes applied? Where should I look next?
Thanks

 

I jacked up the front and rear of the truck and spun all the wheels and the fronts spin with almost no friction and they continue spinning when I stop turning them. The rears turn but stop very quick after I stop spinning them. I also loosened the master cylinder bolts about halfway in case it was being slightly depressed and that didn't change anything either. Is it possible the new pads need worn in and will loosen up in time?

 

This is my first time with these, they have a strange mounting setup with a wedge and a spring. I thought I greased them up good, My uncle says he's worked on them before on an old ford, I'm going to have to take these back apart and see if I can see something binding and have him take a look.

 

Okay, I had to tap the slides in with a hammer, they went in pretty easy once they were at the right angle and lined up correctly. I can move the front calipers up and down a little bit when the brakes are released but not the rears. The front brakes do apply.