I'm redoing the rear brakes on an 8 3/4 suregrip from a 68 RR. The drums are 11"x3". I was looking at the new spring and bracket kits but they only listed them for 10" rear drums and 11" front drums. Are the 10" rear kits the same as the 11" or are the 11" fronts the same as the rear? I believe they are from Carlson.