Pretty sure the rears are 6". The spokes are slightly different than the fronts, and have a different backset. Center caps are also different. I bought some aluminum Center caps from Hughes, they fit the fronts, had to machine the rears to fit.
Center caps have to be different because the OE ones sit deeper in the hub register and can't accommodate the grease cap on the rotor when installed...pretty well documented swap. No factory bullitt wheel has a 6" backspace...factory (and factory mimic'd) 17x8s have 5.72" backspace (30mm offset) for 99-04, and 6.295" (44mm offset) for 05-09 year models. There are some 17x9s with a 5.94" backspace though...
