UMI Performance 64-72 GM A-Body Rear Lift Bars-Bolt-InThe bolt on lift bar set up from UMI requires no drilling, welding or cutting making it a true bolt on. The UMI rear lift bars replace the factory rear control arms adding traction while not changing vehicle ride height. Lift bars work with axle torque to load the chassis of the car, forcing the rear wheels downward pushing the tires into the ground resulting in harder launches and improved 60 foot times. The UMI lift bars are designed to improve