Alignment now or after?
As for the bump stops. GM added a spacer to the rear bumpstops for cars with 17" wheels to keep the axle from twisting (one wheel on a bump, the other in a pothole) enough to allow the tire to contact the chassis. I believe that many guys on here run with out them. However, you may want some input from those same people before you try it. SLP sells the spacer.


