When I lowered my 39 in the rear I made lowering blocks and drilled a hole in the lowering block to sit on the spring locator pin to axle , then drilled another hole approx. 1'' forward and made another locator pin to receive the axle,,,,,This set up was not a store bought kit I used the old Datsun(Nissan) springs and all mounting hardware from that pickup when I built that 39