The alignment settings used with the factory control arms worked ok back in the 50’s --- but not now. The tires have improved dramatically and so has suspension knowledge. The only way to get the correct geometry and get the alignment settings up to speed is to redesign the arms. That is where G-Plus control arms come into the picture. G-Plus control arms change the geometry and improve cornering, straight-line stability and reduce tire wear. New alignment settings are provided and can only be obtained with G-Plus control arms. The upper arms are shipped pre-assembled with billet cross shafts, Del-a-lum bushings, ball joints, and bump stops. The arms can be used with stock or dropped spindles. The G-Plus design will keep the tire contact patch flatter on the pavement through the turns and straight-line applications. Note: The upper control arm is all that is required to get the new geometry. The lower arm is highly recommended.