ReadyLIFT offers the new Big Lift Kit for 2019-2023 Chevy Silverado and GMC Sierra 1500 trucks specifically the 8"F-6.5" R Big Lift Kit (44-3985) for 4WD models. This kit engineered for excellent ride quality and handling is not suitable for Trail Boss AT4 AT4X ZR2 or Denali models nor is it compatible with Adaptive Ride Control Multimatic suspension or vehicles with rear composite mono-leaf springs. It's designed for trucks with traditional steel leaf springs identified by square U-bolts. The 44-3985 kit features boxed steel front/rear cross members and a 3/16" thick steel front skid plate. The 1/4-inch steel differential drop brackets are double gusseted and ribbed for strength against torsional twisting. A unique "clam-shell" style lower strut extension preserves factory strut use and alignment using TCT lower bushings for a precise pivot. New tubular upper control arms with TCT pivot bushings replace OE stamped steel arms enhancing strength and durability. The rear lift includes 5" tall fabricated steel blocks with integrated bump stop landings and an add-a-leaf along with new Bilstein 5100 series rear shocks. Extensive testing ensures this 8" lift kit enhances the ride quality of the new GM 1500 4WD trucks. Recommended tire sizes are 37x12.50 on 20x9 0 offset wheels with no trimming and 37x12.50 on 20x10 -18 offset wheels with minor trimming. Trimming areas include the front valance felt liner edges and mud flap. The use of the Auto 4 Hi feature is not recommended with this kit. Key features include maintaining factory ride and handling clearance for up to 37x12.50 tires on an 8-inch kit the proprietary lower strut clamshell design tube steel upper control arms with maintenance-free pivot bushings and 1-ton ball joints 3/16-inch steel plate cross members and skid plate anti-torsion differential drop brackets fabricated steel rear lift blocks and premium Bilstein rear shocks. The kit also includes the ReadyGuard Powertrain Warranty.