Our 1963-72 Chevy truck fully dual adjustable panhard bar/trac bar is a must when lowering the rear of the vehicle 4″ or more with lowered coil springs and or lowering blocks.New Design eliminates flex and rear end movement during hard cornering unlike smaller diameter bars on the market. Double adjustable ends makes dialing in you rear end easier by not having to remove 1 end to adjust each time. Centers the rear end and allows the vehicle to drive straight and handle better. Extends approx. up to 3.0compared to stock fixed length bar. Minimum lengths listed.