76 caliper rub on bracket

Got all the parts ready to swap out the front brakes on my 65 Valiant. Picked up 73-76 spindles, brackets, and ordered 76 calipers for the bigger piston. I ordered the calipers from NAPA and they appeared to fit on first glance. I was trial fitting all the parts to prepare for this weekend and noticed that the calipers are just a touch too big. They touch the sliding contacts on the brackets but the center of the piston bore casting ALSO touches the center of the bracket as well and there is no clearance. I was under the impression that all 73-76 components should be good to swap. I wonder if it's just the caliper castings that are too big? Anyone run into this?