I ordered brake shoes for my 51 3100 and they sent me 2" shoes for the fronts and 1 3/4"shoes for the rear. My drums are 2 1/4"deep.All four of them.The rear shoes that were in it are 2" but they could have been installed by mistake. Is this correct for an AD? Using narrower shoes in the rear? Or did I get the wrong shoes for the rear?---Jack