11. For setup on the rear axle, Marlin supplied us with a U-bolt flip kit and a new set of 5-inch-lift leaf packs including spring perches, weld-on shock mounts and new shackles. First, Toby removed the stock spring perches from the rear axle. Next he bolted the new spring packs to the housing loosely to allow for setup of the new rear driveline. Once the proper angle was set, the new rear-axle spring perches were welded to the housing.