That's a crapper. I'm waiting for my axles to come in and the guy that widened (not narrowed remember?? lol) my 9 inch builds rear disc systems. Originally I picked up a set of front disc/calipers/dust sheilds/brake lines from Rousch Racing where they pull them off brand new Mustangs to replace them with their own. We mocked the calipers up and stuck my rims in and they JUST clear. To a point that I would do a little grinding if I were to go ahead and use them. But, if I change the wheels or back spacing etc, at all, who knows if they would fit then. So I'm going to have to buy all new smaller calipers for the rear. Damn, so I feel your pain. Mark L