I looked into doing the 15" Grand Cherokee rotors and calipers, they are doable on the drum spindles very easily, just wheel fitment was way expensive. Almost 1000 per wheel for the right back spacing. I set up 12" rotors and calipers from a crown vic, cheap to do, easy to get upgraded parts for. Cop cars are abundant and I did my conversion with new rotors for less than $300.00. Tim