Product information updated on 2021-08-25, Manufactured by BellTech - Part Number Belltech 2509, 2007-16 Silverado/Sierra 1500 2 inch Drop Spindles (see fitment notes), (**Cast Steel control arms only**) Only fit 2wd or 4wd with cast steel control arms. 2 inch Drop Spindle, must use at least 17 inch wheels. They will not fit the 2014 and newer 4wd trucks. Fits: 07-16.5 GM 1500 Silverado/Sierra (All Cabs) 2wd Only 07-14 GM Tahoe/Yukon/Avalanche/Escalade/Denali (2WD/4WD) 07-13 GM Suburban/Yukon XL 2WD/4WD (Note: CAST STEEL OEM UPPER CONTROL ARMS ONLY), Since 1983 Belltech engineers developed one of the industry firsts that enabled the Sport Truck craze, the Belltech Drop Spindle. By relocating the wheel mounting point a.k.a. spindle pin higher on the spindle casting, our engineers were able to provide a 2-3” lowering without affecting any other suspension or steering geometry, not even the shock absorber! Belltech Drop Spindles offer a 2 or 3 inch drop depending on the application, while improving handling and retaining factory ride quality. Belltech spindles maintain critical suspension geometry and eliminate excessive ball joint, shock and tire wear common to other methods of lowering. Each spindle is built from OEM grade high strength ductile iron, providing the structural integrity to meet and exceed all factory specifications & requirements.