Nope the calipers are totally different between teh 2x's and 4x's. But the rear axles are the shiat for using on a mini truck! They are full floaters that use the same wheel bearings as a standard 4x front hub. So all you have to do is swap the big 6 hubs out for some mini truck hubs and space the axle shaft about 3/4". Then make a bracket to hold the caliper and there you have it a factory full floater rear. Your 3rd will swap right into it too.