These adjustable torsion keys can raise your Silverado or Sierra 4WD 1 - 3" in the front. Can be installed in about 1 hour. These torsion keys are CNC machined out of Grade 50 plate steel and then powdercoated black to match you factory suspension. They are far superior to stock cast keys and much stronger than forged torsion keys. This kit is the strongest on the market and come with a 100% satisfaction guarantee and a lifetime warranty. It will come to you complete with all the hardware and instructions. All MotoFab lifts products are proudly made in the USA with USA sourced materials!