Chromoly Pro-Joint (GM Pin) for CST Suspension Upper Control Arms CST Pro Joint Ball Joints are ideal for lifted trucks with oversized tires and wheels. Whether running single or dual shocks, the extreme pivot angle of the CST Pro Joint exceeds that of 1" Uni-Balls. The sealed design makes the CST Pro Joint ideal for any terrain. CST Pro Joints are standard on CST Part numbers CSS-C2-8, CSS-C2-9 and CSS-C4-5 CST Pro-Joint Upper Control Arms. The part number for this item is CSJ-C18-7