Boyd liked his Rubicon Express 4-inch YJ spring packs, but they had started to sag after years of hard use. Since the RE springs work so well, Boyd replaced the old RE leafs with new ones. The brand new Rubicon Express leaf springs work as well or better than the old ones did. Boyd also decided to use a new set of Rubicon Express/Bilstein gas shocks. While not adjustable, the shocks are valved perfectly for this application. Drivetrain Unlimited rebuilt a salvage yard Ford reverse Dana 44 using Warn hardened axles and HD hubs, 4.10 gears, and a Detroit Locker. A Howe steering ram and HD steering gearbox makes turning the YJ easy in the rocks. Boyd installed a M.O.R.E shackle reversal kit.