Detroit Speed's front subframe is a bolt-in replacement for the original stock subframe. It improves the handling and ride quality by utilizing DSE'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/in Spring 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! Double Adjustable Shock: This is the most race winning shock JRI has in its stable. With its two independent adjustments and the enormous range of adjustment it can be set to the exacting demands of the driver and performance levels required while providing excellent ride quality on the street.