1955-57 Small Block Chevy Chassis Headers/Rack and Pinion Black H60103BK. If you are running our Unisteer rack & pinion, you will need these headers. They allow the steering shaft to pass through on the driver’s side and are a shorty style for maximum ground clearance. Features 1-5/8″ primaries with a 3″ collector. Tubing Thickness: 12 …