1. Our control arms began life as 1-1/2 od by 0.120-inch wall chrome-moly tubing and 3/16-inch cold-rolled steel plate. After figuring out how wide the rear arms needed to be to accommodate both the shock and the airbag, we bent the tubing and attached the bearing housings that we bought from McKenzie's Performance Products in Fullerton, California. The arms were gusseted and TIG-welded together. The arm pictured here is one of the rear lower control arms.