The upper control arms (UCA’s) are stronger than the stock arms and are 100% bolt-on. The UCA’s are a direct fit and will work on trucks that are have leveling kits, or lift kits. Again, This is for those trucks with Factory Steel Upper Control Arms. It is a must have to add strenth and performance to your truck while on or off road. Weak OEM ball joints present problems by limiting suspension travel potential, especially when using 2” or more lift on your truck. The UCA is allowing for smooth and clean wheel travel without worrying about factory ball joint bind; also correct alignment geometry on lifted applications.