The Dirt King ball joint upper control arms are engineered to improve suspension geometry, enabling additional front lift when paired with Dirt King shocks. Lifting a vehicle with stock upper control arms compromises both the geometry and structural strength due to excessive articulation at the factory joints. The Dirt King arms address these issues with improved caster settings for enhanced handling and re-engineered pivot angles for increased articulation. The inner pivots feature Probearing SilentSpin Hybrid bushings, offering the ideal combination of a free-spinning inner sleeve, typical of poly bushings, with the maintenance-free and greaseless advantages of OE elastomer bushings. Additionally, the standard ball joints have been upgraded to heavy-duty Moog ball joints ensuring superior durability. All components of these upper control arms are rebuildable or replaceable, promoting long-term durability and ease of maintenance. These arms arrive preassembled with detailed instructions for a straightforward installation.  Specifications Wheel Travel: Additional 1” of down travel compared to stock Amount of Lift: Allows for 0-3” of lift Track Width: Stock Maximum Backspacing: 4.75” Minimum Rim Size: 16” Wheel Travel / Lift The Dirt King upper control arms must be paired with aftermarket coilover shocks to lift the vehicle. The Dirt King arms offer an additional 1” of down travel compared to the stock upper control arms. These arms are compatible with Dirt King, King, Fox, Bilstein, ADS and Icon coilovers. Do not install these upper control arms with coil spacers paired with extended length aftermarket shocks.  What's Included Chromoly upper control arms Probearing SilentSpin Hybrid bushings Moog ball joints Ball joint caps Dirt King sticker pack Installation instructions   Features CAD designed  Formed steel bushing gussets Constructed with 4130 chromoly tubing Preassembled for fast installation Maintenance free bushings Zinc plated components for corrosion resistance Durable black powder coat Professionally MIG welded Proudly made in the USA   Instructions DK-631991 Instructions DK-635991 Instructions   Compatibility 2007-2018 Chevy Silverado 1500 2WD / 4WD 2007-2018 GMC Sierra 1500 2WD / 4WD