I have a 99 xj I'm putting a 4.5" lift on and was wanting to know how much I should adjust my new lower control arms from the factory setting? The measurement from eye to eye on my stock arm is 15 3/4". Thank you for any advise.

 

They will need to be lengthend from stock. start here at 16 1/2": http://www.lunghd.com/Tech_Articles/..._Arm_Chart.htm.
you may need to fine tune to get the caster and pinion angles right.

 

I got mine at 4 1/2 inches set to 16 1/4. I bought them from "Ironman Andy" from this forum and couldn't be happier...Tj