Supreme Suspensions - Chevy Silverado GMC Sierra 1500 CNC Machined Differential Drop Kit Including Bolts 4WD 4x4 (Black) PRO FITMENT: 2008 - 2018 Chevy Silverado 1500 4WD and New Body Style 2007 Silverado 1500 4WD. ONLY Fits 6-Lug Models CONTENTS: 2x Aircraft Billet Differential Drop Spacers, Installation Hardware, Installation Instructions and Pro Pack. BENEFITS: Improves axle alignment and eliminates vibrations. Solid light weight Aircraft Billet protected against rust. INSTALLATION: Installation is easy and takes between 1 - 2 hours. No special tools are required. TECHNICAL NOTES: Maintains factory ride quality.