UMI adjustable rear control arms for 1971-75 GM H-Body improve traction.The UMI Performance adjustable rear control arms kit is designed for 1971 1975 GM H Body vehicles. The kit includes both upper and lower control arms with high quality Teflon lined spherical rod ends to eliminate rear suspension bind and allow for proper suspension articulation. The rod ends also act as solid bushings for drag race applications, reducing bushing deflection. These adjustable control arms allow for fine tuning of the rear end position