Detroit Speed's front subframe is a bolt-in replacement for the original stock subframe. It improves the handling and ride quality by utilizing Detroit Speed's unique suspension geometry. It is the ONLY subframe in the aftermarket industry with hydroformed frame rails. The hydroformed frame rails feature strength and stiffness, precise quality and repeatability. Hydroforming preserves the steel's strength and stiffness because it is performed at low temperatures, unlike traditional high temperature processes which decrease material strength.Spring Rate: 550lbs/inSpring Free Length: 8inUp to a 10" wide wheel can be packaged without modification to the inner wheel wells. Both the main and secondary crossmembers are stamped for structural rigidity. SBC, BBC, LS1, LS2, and LS7 engines have been designed as a direct bolt-in into this subframe.Our subframe has been designed, engineered, and developed for the road and track. This subframe blends the benefits of current OEM technology and aftermarket performance into one product!Single Adjustable Shock:Includes all features of base shock with 'Detroit Tuned' valving plus installed rebound adjustment with the simple turn of a knob while providing excellent ride quality on the street.