Product updated on 2021-01-08, BellTech - BEL:4454, 1999-06 Silverado/Sierra 1/2 Ton (Ext/Crew Cab) 1 inch Drop , 99-06 Chevrolet Silverado/Sierra 1/2 Ton (Ext/Crew Cab) 1inch Drop , Here is the situation. You do your research and figure out what lowering you want to match your wheel and tire combination, and install the kit. Now you are thinking that you really wanted another 1 inch lower on the front. What do you do? If you have a set of the Belltech “PRO” Coils in your kit it’s not a problem. This Belltech advanced lowering kit which includes Belltech‘s high quality coil springs and engineered vehicle specific upper spring or strut mount spacers allowing you to have 2 lowering height options with one purchase.