Detroit Speed's Hydroformed 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!The subframe is available uncoated and unassembled for your SBC, BBC, LS, or Pontiac engine. We also offer the subframe powdercoated satin black and assembled.Base Shock:The DSE/JRI 'Detroit Tuned' base shock is a 'pure blood pedigree' racing shock in its most efficient form as a non-adjustable unit. Although non-adjustable, it shares all the increased dynamic responses of all the JRI adjustable models while providing excellent ride quality on the street.