These BDS Suspension BDS121152 Upper Control Arms (UCAs) for the Chevy Suburban models (w/aluminum or stamped steel factory control arms) are designed for improved strength, added suspension travel and elimination of ball joint binding on leveled and lifted Suburban 1500 vehicles. Built from high strength 1.5″ OD x .120-wall tubing and fully welded for strength and durability. They use an indexed ball joint cup to correct the ball joint positioning for when used with leveling or full lift kits. Factory style durometer-specific rubber bushings are used for longer lasting durability (more durable than poly bushings). Featuring premium quality MOOG ball joints for smooth, quiet operation and superior corrosion resistance to arms that feature uniballs, poly bushings or heims.