Supreme Suspensions - Chevy GM 2500HD 3500 HD 4x4 1-3 Inch Front Suspension Lift + 1 Inch Rear Suspension Lift + Shock Extenders PRO FITMENT: 2011 - 2018 Chevy Silverado 2500HD, 2011 - 2018 Chevy Silverado 3500HD, 2011 - 2018 GMC Sierra 2500HD and 2011 - 2018 GMC Sierra 2500HD (4WD). For models with 8-lug axle configurations. CONTENTS: 2x Cold-Forged Carbon Steel MAX-Torsion Keys, 2x Billet Aluminum Rear Lift Blocks, 4x Extended Plated Steel U-Bolts, 2x Carbon Steel Shock Extenders, Installation Hardware, installation Instructions and Pro Pack. TECHNICAL NOTES: 1 - 3 inch front and 1 inch rear suspension lift. Maintains factory ride quality. INSTALLATION: Easy installation takes 2 - 4 hours. A torsion bar puller is required. An alignment is recommended after install. BENEFITS: Improves the look of your truck and increases ground clearance, allowing you to fit larger custom rims and tires. Factory shocks can be reused.