The 44-39420 lift kit utilizes the very best in ReadyLIFT engineering with boxed steel front/rear cross members and full-width front skid plate constructed of thick 3/16" plate steel. New 1/4-inch boxed plate steel differential drop brackets feature a double gusset and boxed center rib to take the abuse of front differential torsional twisting.   Our 4" lift kit features heavy-duty angled and offset top mount strut extensions that realigns the struts to optimize shock performance and minimize wear. A specially designed lower mount strut pre-load spacer offers the added benefit of a slight increase in spring rate to better handle the larger wheels and tires that will find their way onto this new lifted truck. To lift the rear new fabricated steel rear blocks with integrated bump stop landings have been added as well as new rear shock extensions.   With months of engineering and development and more awesome features than we could possibly mention the bottom line is this new Big Lift Kit is the best 4" lift kit you can install on a new body style 2019-2023 GM 1500 4WD truck! Thousands of miles of road and trail testing have proven our new 4" lift kit makes these new GM 1500 trucks ride better than stock! Wheel and tire fitment information: 44-39420 6" Lift Kit - Recommended max tire with no trimming: 20x9 0 offset - 35x12.50 tire. *Max with trimming: 20x10 -18 offset - 35x12.50 or 325/60R20 *Trimming requirements for larger than recommended wheel/tire include front valance front felt liner edge rear felt liner edge and front-rear well edge mud flap.