Hotchkis Sport Suspension 1206AA 1973 - 1977 GM A - Body Double Adjustable Upper Trailing Arms. Improve the traction and handling of your GM 73 - 77 GM A - Body Muscle Cars with the Hotchkis Double Adjustable Upper Trailing Arms. These exceptionally durable arms allow for easy pinion angle adjustment for reduced vibration and increased traction. Our exclusive Swivel - Max bushings offer non - binding articulation during suspension travel which improves traction and rear suspension efficiency. Finished in gloss black powder coat and clear anodizing these Double Adjustable Trailing Arms look great and perform well. Features Double adjustable design with right and left hand threads. Lightweight strong 1 - 12 in. billet aluminum center sections with color Hotchkis logo. Hotchkis exclusive high articulation easy to lubricate Swivel - Max bushing. 100 TIG - welded heavy duty steel construction. Durable black powder coat finish. Benefits Easy in - car pinion angle adjustments for improved traction and reduced wheel hop. Heavy duty construction for long lasting durability on the street or track. Swivel - Max bushings allow for suspension articulation without unwanted longitudinal flex. Complete ready to bolt - in and includes polyurethane rear end housing bushings. Supersedes 1206A.