Our 4 Ultimate System provides less lift than our 6 RTS(TM) system but still allows use of 33 or 35 tall tires with cutting for street and offroad use. We have developed this system utilizing replacement upper control arms constructed of 1.50 OD .120 thick wall DOM tubing that attaches to heavy-duty Fabtech ductile iron steering knuckles. The factory torsion bars remain in the stock position and use new forged adjusting keys to provide the proper amount of lift. There is no loss of ground clearance with this system as the stock lower control arms, torsion bars and front differential do not need to be relocated. This 4 Ultimate System will level the stance of the vehicle compared to the factory nose-down rake with no change to the rear suspension. For those customers that require a factory nose down appearance an optional 1 rear block kit is available (2500HD Part # FTS21110) (3500HD Part # FTS21111).