Hotchkis Sport Suspension 1213 1958-1964 Chevrolet B-Body Adjustable Upper Trailing Arm. Improve handling and traction on your 58-64 Chevrolet B-Body by upgrading your flimsy stock trailing arms with our Adjustable upper trailing arms. Fabricated and TIG-welded from .120 wall rectangular tubing these adjustable arms feature greasable bushings grade 8 hardware and a durable powder coated finish. Note: These arms are sold each. Please verify if your vehicle requires 1 or 2 upper arms. Specs: The stock Chevrolet upper arm center-to-center length is 13-3/4 in. The maximum suggested center-to-center length of the Hotchkis upper arm is 14 in. The minimum suggested center-to-center length of the Hotchkis upper arm is 13-1/2 in.