Adjustable rear lower control arms are not used to adjust pinion angle and are not required if lowering your ride height. We offer adjustable rear lower control arms (LCAs) to allow for two things. For those installing very large tires they allow you to push/pull your rear end front/back to gain the tire clearance you need in the wheel well. Secondly, many fabricated aftermarket rear ends do not always have the control arm mounts welded on "perfectly". The adjustable LCAs allow you to square up your rear end. With adjustable LCAs and Panhard Bar installed you can do a four wheel alignment to get a perfectly square set up.
Many of our LCAs only come adjustable due to the fact that the mounting ends are threaded (rod ends, Del-Sphere, etc.). You may desire these mounting ends but don't feel you need the adjustment feature. Know that all of our adjustable components ship to you jig set at OEM length. If you have no desire to do any adjusting, simply install them as they are shipped and you will be good to go.