I hope you have better luck with SLR than I did. I ended up replacing the SLR upper control arms with Calmini's after 5 months because I couldn't get it aligned and Spencer Jr. did nothing to help. I had his National Spring leaf pack that never provided enough lift to match the front and was sagging badly after 6 months. I added a AAL to an already big stack of leaves to get the height back up. His diff drop has twisted twice in the mounts so that the inner passenger CV joint rubs the frame. The SLR torsion bars have settled over a foot, it's my monthly chore to crank them back up. I'm not alone, after I came out on XOC with my problems I get an email or two a month from people that have problems with SLR.