Spring relocation kit?

I just ordered my relocation kit from bill at THE CAR FARM. These are shaped to match your frame unlike the mopar performance ones. Kit is about $119 or so. I cut out my wheel tubs and should be able to fit 325 50 15 in there. I have some 12" slicks that look like they will fit. Why would you do the relacation and not the wheel tubs? jared
WHERE IS THE CAR FARM LOCATED ? IM IN CALIFORNIA . THANKS JOHN