1973 450SL. I purchased new rear calipers (1234200683 new) the left one went on great, the right one is hitting on the rotor backing plate where there is a cutout for caliper. the flange on the caliper is thicker. (circled in photos) I had some old calipers from a w123 that are the same as new ones purchased that should go on R107 also, so I know they are correct. I know I have to change out the brake hoses and eliminate some extra parts, that isn't the problem. Anybody else have this problem? Do I bust out the grinder?

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