Blunt,
I bought a spare to rebuild. It has taken a long time to get my parts together. Make sure the roller axle shaft and the worm gear are good. They are expensive. If you need either one it might be best to buy a rebuild for $400 +- $175 core. The groves need to be in good shape and the shafts need to have a good fit where it fits inside the 2 brass bushings in the lower end of the steering box housing. There is also a brass bushing in the cap where the top of the axle shaft rides. I had to fnd a good used cap because mine was worn.
I replaced upper and lower seals and top gasket. I also replace both bearings and both races. I don't think replacing all this will give you any more adjusting room with the screw on the top of the box. I think that wear on the axle shaft is taken up by that adjustment. Having replaced the bearing and races, one side of each bearing rides on the worm gear. Mine had some wear where the bearing rides but a new worm gear is about $200. The bearings price is like $46 each but 2002AD has an alternate source from somewhere. Their price is $7.42 each . The races are $28 and $19. The races are different although the bearings are the same.
If you have any more questions, just let me know. This is my first rebuild of an 02 steering box bit I have rebuilt the box on my 1930 Model A Ford. I am amazed at how similar they are.
Tiger75