All upper tubular and lower boxed trailing arms use polyurethane bushings on both ends, while upper adjustable and lower tubular trailing arms use a spherical ball or rod end assembly on the chassis end to eliminate bushing bind, allowing the suspension to move smoother for better control. This keeps the tires planted firmly on the ground for improved traction and a more predictable, better handling car. Trailing arms are powder-coated gloss black for a long lasting finish. Boxed Trailing Arms are constructed from 0.120'' wall cold rolled steel tubing for maximum strength and flex elimination. These trailing arms have fluted, greasable polyurethane bushings, which are superior to the stock rubber bushings. Tubular Trailing Arms are constructed from 1-1/4'' diameter, 0.120'' wall steel tubing which offers increased strength over other designs but also has the added advantage of lighter weight. These trailing arms have fluted, greasable polyurethane bushings, which are superior to the stock rubber bushings. Heavy-Duty Adjustable Trailing Arms allow easy rear suspension adjustments for optimum handling and traction. Simply loosen the jam nuts and adjust the pinion angle without removing the arms from the vehicle. They replace soft OE differential bushings with polyurethane differential bushings, and they use a spherical ball or rod end assembly with UHMW polyethylene bushings on the chassis end to allow the rear suspension to move more freely and eliminate bushing bind. Adjustable Tubular Lower Trailing Arms are offered in both aluminum and steel. These arms are the ultimate in weight savings and adjustability, and they feature QA1's premium self-sealing and self-lubricating X Series (heat treated chromoly steel) or A Series (aircraft aluminum) rod ends. Kits include (2) lower control arms with rod ends and jam nuts. All parts sold in pairs.