adjusting the upper control arms won't throw the geometry "out of whack" if done properly (which I'm sure Coastal will do). He obviously has to keep an eye on his pinion angle and make sure the rear stays square from side to side. Not sure what lowers he has, but probably what will need to happen is if it's anything like my lowers, they'll have to cut the welds on the LCAs, adjust the positioning of the LCA and UCA, reweld the LCA.