I did this swap several years ago on my GP. I used everything from a 2wd blazer and had no interference issues the shocks even bolted up in the stock location with no adapters required. I was also able to make the blazer e brake cables work. Im not sure if there would be clearance issues with the 4wd backing plates mounting the caliper at the front. Though I do know that both types mount in the same position relative to the center pumpkin of the rear, the reason for the deeper rotor hat on a 4x4 is simply due to the axle flange sticking out further from the housing than a 2wd. So if the calipers wont hit the frame mounted forward of the axle you can just get 2wd rotors and it will fit.