Zone Offroad Chevy/GMC 4.5" Suspension System - ZONC27/C28

*IMPORTANT*: GM is producing several knuckle/control arm configurations in 2014-2017 models trucks. Cast Steel control arm equipped models will require the "Cast Steel Control Arm" kit (#C27). Stamped Steel and Aluminum control arm equipped models will require the "Aluminum Control Arm" kit (#C28). Be sure to verify which factory control arms your truck has before ordering your kit by referecing our help image below (click image for larger view): All wheel drive models require drive line modification Frame bracket modification and minor welding required To reduce trimming required with 20" wheels, 5.75" backspacing recommended Will not fit models equipped with magnetic ride control. Factory 17" and 18" wheels cannot be reinstalled due to tie rod end interference Take your Silverado/Sierra 1500 to new heights with this 4.5" lift kit from Zone Offroad. Kits include everything needed from high strength crossmembers and steering knuckles to strut spacers and rear block kit to level out the stance. Get the look, performance, and capability your truck deserves with clearance for up to 33" tires. Features & Benefits Corrects suspension, steering, and drive-line geometry for great on-road handling and improved off-road performance. FMVSS No.126 compliant to work with your vehicle's stability & traction control systems without lighting up your dash like a Christmas tree. Heavy-duty differential skid slate improves offroad protection. High-strength, 1/4" steel construction crossmembers correct lower control arm geometry. High-strength, CNC machined, replacement steering knuckles improve strength while correcting steering angles. Multi-point differential relocation brackets secure front differential for improved CV operating angles. Proudly made in the USA. Rear lift block and longer U-bolts for easy installation and level stance. Weld-in frame support plate for additional strength. Recommended Tires & Wheels (Trimming may be required) 33 x 12.5 with 17 x 9 and 5 in. Backspace 33 x 12.5 with 18 x 9 and 5 in. Backspace