Developed by Cobra Automotive and race proven, these springs have several unique features, including a smaller eye on one end to accommodate the slider shackle, along with de-arching to lower the car automatically. These springs are de-arched 1” to lower the rear of the car and increase the spring rate. A special front solid eye bushing kit is included. These bushings are made of a combination of aluminum and high impact polyethylene to eliminate lateral deflection and body sway while allowing free movement. These race springs can only be used with our slider mounts. Welding is required to mount rear sliders. These springs are designed for use on full competition cars. Instructions included.