Weak OEM ball joints and upper control arms present lots of problems by limiting suspension travel on lifted trucks. The more you lift, the more likely you are to begin having issues. Uni-Ball Upper Control Arms by CST Suspension feature a uni-ball design and come fully assembled. The part number for this item is CSS-C2-17 and this PAIR of upper control arms fits 2007-2017 Chevy Silverado, GMC Sierra (1500 2WD Models w/ OEM Stamped Steel or Aluminum Suspension) .