'73 Swinger brake drag

Well, I think I've found the problem, I'm just not sure how to correct it. The pads are always touching the rotors because the space between the pads is exactly the same as the width of the rotor! As I said, we replaced the calipers so I know those are correct. Who knows what the Previous Owner did, but obviously something is wrong... Any way to tell what's going on without just buying new correct pads and rotors to compare?