I measured my castor and this is what I came up with. The first pic is of the driverside, the second of the passenger...I popped the zerk out of the upper ball joint placed the angle finder on top of the inner C, I was in level ground as well. I'm running a 5.5" lift with RC cad brackets, lca's at 16", uca's at 15.5", per RC...both CA's are adjustable. Can someone help me interpret this readings?? Thanks!!

 

When I was dealing with that I used this as a guide.
http://go.jeep-xj.info/HowtoAlignment.htm
This shows to measure off of the diff rather than the C's. Having non adjustable LCA's at the time I learned that I needed to shim my lower control arms which set my caster right back to stock. Hope this helps.