This SuperLift 4" suspension system features American Made coil springs with matching OE coils rates that are specifically designed for Ford F250/F350. The SuperLift coils can be smashed to the bottom and will always come back! No, that doesn't mean they are stiff, the key is using the correct size wire with the correct spring rate to offer the perfect ride and still hold up over time. Radius arm lowering brackets are used to restore proper caster angle / alignment. Other components included: front compression travel-stop relocation brackets, track bar relocation bracket, drop pitman arm, front anti-sway bar extensions, and a steering stabilizer bracket. New anti-wrap lift blocks and new u-bolts raise the rear. Add in the Nitro shocks and this Superlift 4" kit offers one of the smoothest, controlled ride available for your Super Duty!