I am sure that it is possible, and I have some rims that would fit that I would sell to him, but I am not sure why he would want to do that... would it be able to hold more weight and tow more? that is the only benefit I could see...
Dont quote me but I think I heard that he might have to change out the rear axle if he wants to do that, but the front should be "relatively" simple. but then again it might be more trouble than what it's worth...
just my thoughts
