I just put mine on this weekend. Everything I read said it is best to set the LR UCA at their zero setting, which is actually a +2 over factory, then have the alignment done and adjust from there.
I actually just did the same and put them to +2, and now it seems that i have more tire rub than before. Not to sure if it would be better (for the tire rub) at a different setting to try and push the tire ahead a bit.