2006kxf250

I have an 2008 4door unlimited with a 4 in lift with stock control arms my question is my caster is out pretty bad and I am going to buy adjustable control arms but I am on a budget and wanted to know I could get away with just uppers or just lowers here is a pic of my alignment sheet

rays0852

Hopefully WOL chimes in on this but I think in the front you will at least need lowers. I would start with them and if you need to you can always add the uppers later.
Currie makes one of the more affordable sets out there although you may want a matching set to your lift brand.

http://northridge4x4.com/proddetail.php?prod=CE-9807FLA

rinkishJK

U can use uppers or lowers to set a higher caster.... Problem is when using uppers only some arms don't go much shorter than stock, which is what u need to do with upper arms to increase caster.
If it were me I would just get a set of good front lowers such as tf like I run, or rk, ft, jks, etc.
Most ppl including wol recommend lowers set to 23", which works for most ppl.