Our 1963-72 Chevy truck drop crossmember is specifically designed for Chevy trucks that have a 4″ drop or more. Increases ground clearance on your lowered truck. Includes bolt on trailing arms mounts with anti squat provisions up to 4 degrees and are far superior to the welded items on the market. Our crossmember is based on the General Motors design. Bolt on mounts allow for the use of 5 different trailing arm settings. Lower hole is for factory trailing arm position, and is adjustable for up to 4 degrees of anti squat allowing more drive off of corners for better performance. Also allows for harder launches for quicker 0-60 foot times.