2014-2018 SILVERADO/SIERRA 1500 4WD 4" LIFT KIT - ALUMINUM& STAMPED STEEL SUSPENSION ONLY. RTX Off Roadoffers 2014-2018 GM 1500 1500 4WD truck owners a 4 inch lift kit solution that allows for up to a 33 inch tall tire, or up to a 35x11.50 (minor trimming may be required). The RTX35145 GM 1500 4WD 4 inch lift kit is a greatopportunity to lift yourtrucka true 4inches in front while increasing ground clearance. The RTX35145 4 inch lift kit includes heavy duty steel front strut extensions and heavy duty tubular steel upper control arms designed around 4 inches of front lift geometry and includes ball joints specifIc to aluminum and stamped steel front suspension trucks. This kit includes new 3" tall rear blocks with longer u-bolts and rear shock extensions so you do not need up purchase longer aftermarket shocks. New CNC machined front differential drop spacers lower the front diff to retain optimum CV angles while a new heavy-duty skid plate add protection to your 4WD running gear. This kit is designed for use on 4WD model trucks with Aluminum and Stamped Steelfront suspension.