Make sure whoever does the install loosens the control arm bolts to let the bushings reset to their new ride-height position.. AND that they wait until it's at ride height before tightening. I'm starting to be more and more sure that uneven bushing position is why my rig leans. Which also puts more strain on the bushings that are loaded up.
This is exactly what Rob (@Taco2Cruiser ) did on mine, he even let me help and carefully explained every step. I have about 1/2" difference between right and left, but I'm ok with that. Actually it may have evened out by now, I should check it again.
A good alignment after from a shop you trust is also very important. Hand the tech an extra $10 before he gets started so he'll spend a few extra minutes getting it "right".