Comprehensive Compatibility: These upper control arms are compatible with a wide range of vehicles, including the 2001-2010 Chevy Silverado and GMC Sierra 2500HD/3500HD 4WD, 2001-2004 Chevy Silverado/GMC Sierra 2500, 2001-2006 Silverado/GMC Sierra 1500HD, and 2003-2009 Hummer H2, providing a versatile solution for various truck and SUV models. The Grease Ball Joints: Each control arm comes pre-installed with grease-injectable ball joints, plus an additional pair of replacement ball joints is included. The ball joints support grease maintenance for easy upkeep and long-lasting performance. Their dust- and dirt-resistant construction effectively extends service life. Premium PU Bushings: Featuring high-performance polyurethane (PU) bushings, these control arms offer superior resistance to wear and tear compared to traditional rubber bushings. PU bushings provide better handling and a more responsive driving experience, ensuring that your vehicle's suspension remains tight and controlled. Enhanced Suspension Performance: Designed to accommodate a 2-4" lift, these control arms provide superior handling and stability, improving overall suspension performance and ride quality. Easy Installation: Engineered for a direct bolt-on replacement of OEM control arms, the installation process is straightforward, with no need for additional modifications, making it convenient for both DIY enthusiasts and professional mechanics. Serviceable Components & Long Warranty: Comes with replaceable ball joint dust covers, grease fittings, and sleeves. Designed for easy maintenance and backed by 10-year warranty on the tubular arms and 2-year warranty on bushings and ball joints. Front Upper Control Arms for 2-4" Lift - Fits 2001-2010 Chevy Silverado/GMC Sierra 2500HD/3500HD 4WD, 2001-2004 Chevy Silverado/GMC Sierra 2500, 2001-2006 Silverado/GMC Sierra 1500HD, 2003-2009 Hum-mer H2