ReadyLIFT '' Adjustable 5'' to 6'' Lift Kit System is made to fit the 2011-2019 Chevy Silverado / GMC Sierra 2500HD/3500HD 2WD/4WD trucks. Equipped with four specifically tuned Falcon 1.1 Monotube performance shocks this kit is specifically designed to give you a quality lift and off-road strength while maintaining the factory ride on the street. Lift your GM 2500HD / 3500HD truck the right way!   This system features precision-designed laser-cut and CNC-formed sub-frame assemblies that directly bolt in. Custom-formed modular iron knuckles are engineered to provide perfect geometry ride and handling performance. The integrated differential drop bracket system will ensure correct CV axle angles on 4WD applications and maximum performance in 4WD mode. The one notable feature gives you the ability to adjust the lift height from 5'' to 6'' while maintaining the factory ride. The front ride height adjustment utilizes the factory torsion keys with ReadyLIFT '' torsion bar drop brackets. To elevate the rear this system includes OEM quality cast iron rear blocks that do not sacrifice ride quality. The kit includes tough steel bump stop extensions skid plate and sway bar end links. The stock 20 '' wheels can be used or a 9'' wheel w/ 4.75 '' - 5.5 '' backspacing. Stock 17 '' or 18 '' cannot be run with this system due to clearance.     NOTE: Some SRW (Single Rear Wheel) models may require custom U-Bolts to accommodate the factory tow package. Will not fit DRW (Dual Rear Wheel) applications without custom U-bolts. Towing Capacity will be reduced with the installation of this kit. This kit is primarily designed to only be driven in 2WD at speed on public roads and that 4WD is only to be used off-road or in adverse slow speed conditions due to drive line vibrations at high speeds. A double cardan driveshaft may be required to help eliminate some of the high-speed 4WD front driveline vibrations when kits are 5-8'' high.