I have to agee with what Pasadenahotrod said. sagging on the drivers side is usually due to the rig only having the driver in it most of the time. bigger the driver, more noticable the sag. I weigh 260 so I know from where I speak buy from years of experience working on front ends and suspensions I can safely tell you that a lot of vehicles don't sit square from the day they left the factory.
Park the jeep on a level area, Bounce the corners by hand a bit to settle it out and then measure it at all 4 corners, same spot on each wheel well works good, then see exactly what the difference is and go from there.
The lift kit with it's new springs should fix it or if you don't want to lift it take it to a good spring shop and have them rework the springs.
Most major cities have at least one automotive spring shop around.