What I gave you was an abbreviated version of what needs to be done. Please don't get the impression you can do this without pulling the steering box. Before tackling this, *get the factory service manual*; it will take you step by step. I would have to look in my XJ manual to be sure about the 1/2" set back marking but I'm pretty sure that's the spec. I also have the adjustment procedure in my Chiltons S10 manual.... which is really surprising. If you can lay hands on one of the Chiltons S10 books (the larger book, not the small one), it should have the adjustment procedure. In fact the removal procedure is pretty much the same for both vehicles. This is a good weekend project; you'll use most of Saturday pulling, adjusting and reinstalling. The overnight part comes from servicing the power steering system since you will drain just about all the fluid to do this job. Once the box is removed you'll need to drain as much fluid from it as possible. When reinstallation is complete, there will be a *lot* of air in the system which will require an overnight "rest" to fully purge.
The overcenter adjustment, when adjusted correctly, will cause a very slight increase in torque as the stub shaft is rotated through the straight ahead position. The correct overcenter adjustment will create a very slight resistance from 45-30 degrees of stub shaft rotation either side of straight ahead. The increased resistance causes you to apply slightly more torque to rotate the stub shaft; hence the increase in torque reading..... and this is measured in Inch-Pounds *NOT* Foot-Pounds (12 in/lbs = 1 ft/lb).
mike