5. To lift the rear of our GM truck, we opted to keep the factory leaf springs and install an Offroad Design 4-inch-lift shackle flip. This requires the removal of the factory shackle-bracket and rivets. A grinder, air-chisel, or torch can be used. We prefer to use our Miller Spectrum 375 X-Treme plasma cutter that can literally hose away the heads of the rivets. Shackle bolts sometimes need to be torched to be removed. We were lucky, ours simply unbolted.