Front brakes dragging. HELP!

[1774btcrew]

I have had my 1/2 ton Crewcab short bed done for almost 5 years. When I originally built it I put new calipers on it. My truck has the larger rotors and that is the calipers I supposably purchased(Autozone) . Is it possible they gave me the wrong calipers or could it be another problem? When it was initially done I just figured they would wear in but after 5 years they still drag. I would really like to get this resolved. I am getting 26MPG highway right now but would really like to improve it and I know if I could get the brakes to quit dragging I am sure it would help. Is there a part number cast into the calipers I can check? I appreciate any help.

I guess I should add that I am using the original 3/4 ton Brake Booster and proportioning valve. I bought a complet heavy half ton frame and unbolted the complete front crossmember. Rolled it under mine, cleaned and greased the bearings, turned the rotors and put new calipers on it. That is all.