Ralleye wheels usually won't have the same clearance as the steelies or cops do.

I did some brake fitting on the front of my 'Cuda for Viper brakes and the steelies/cops fit while the ralleye's DO NOT!

It has to do with all ralleye centers being the same be it 14" or 15". They have to make the rim to acommodate the centers on the 15" is the best way I can explain it and you give up some room for brake clearance.