The bearings are larger and the rotors are 12 inches. I did find a machine shop that would redrill the mid size rotors to a 5x5 for $30.00 each. Turns out the circle track rotors that are 5x5 have 5/8 wheel studs that won't work with stock wheels. Who has the best price on a disc brake kit ? Think I going to get a kit and have the rotors redrilled to 5x5.