I am starting my zone 4" lift tomorow. I have read this part a few times to my understanding we are supposed to put an offset washer on the control arm mark out the hole and use a die grinder to offset the hole. Most likely to adjust the pinion angle to reduse vibration. I let you now tommorow if it works.
2003 TJ, (sold)
2005 LJ, 33" BFG KM2, 4" SUSP LIFT (sold)
2012 JK (traded)
2014 RUBICON X unlimited