[Karlitos]

Yeah its casted metal, those two circled pieces are the same distance no matter what, piston in or out. Besides theyre not even on the same plane since the screws extend past the caliper. If his is auto, its more likely to have abs than a stick. check that because that has something to do with it aswell but idk if it changes caliper size. Also make sure your using the right placing on pads. Theres 4 pads total for the rear. Taking one side into consideration there is one that goes infront of the rotor and 1 behind. They fit in the caliper either way but only fit in the rotor one way. Make sure you didnt flip that either... other than that idk.