I am getting ready to do a 2.5" / 1.5" Cornfed Rear Spacer Lift (4) Bilstein 5100. I went ahead and purchased a set of JBA UCA STD to go along with it. What should I tell the shop that is doing the work, along with the alignment, about where to target the caster? I am running 275/70/17 BFG KO2. I have no rubbing on stock suspension now. Seems the consensus is 3.5 - 4.0? Thanks.