Last year we did a hotel rehad with about 1000 Kohler cast iron bath tubs. Since we didnt have access to the back wall or sides we used a ledger board to carry and help us shim the tub. We would wedged a pry bar between the floor and the underside of the tub. With my forearm I would push down on the pry barwich would lift the tub and with my hand I would shim the legs with large metal washers. Sometimes because of the drain we would have to lift the tub about 3/4" again we would shim the four legs and apron.