So, I went out this morning and took my column apart.
The steering box has a 3/4" diameter 36 spline steering box to column coupling point.
On my set up, with the slide nearly completely compressed, the distance between the center of the U joint to center of U joint is about 12" (notice that is not the end to end, but the center of the joint itself) you will need to adjust that length to fit your needs.
The column end is a double D shaft.

The parts you need would be:
1 U joint with a 3/4" -36 spline on one end and a 3/4 Double D on the other end.
12" length of 3/4" Double D shaft (if your slide is extended way out, you may need a longer Double D shaft)
1 U joint with both ends having a 3/4" Double D end.
If you feel the need, you may want to add a vibration dampener. Adding a vibration dampener will reduce the length of the Double D shaft you will need.

The coupling at the steering box is the same on the 96 4x4 as it is on a 92 4x4, and I believe its the same as a the coupling end on a 2wd steering rack.

The hollow shaft on a 4x4 fits over a 3/4 Double D shaft. If you feel a need to have a sliding shaft, you can attach a short Double D shaft to the lower U joint, then attach the bottom of the hollow shaft to that short Double D shaft (pin or weld) and then slide the hollow shaft over top of the Double D shaft that is connected to the top U joint. The hollow shaft has about 6" of useable movement which should leave 2" of the double D to hollow shaft engagement if the lower end of the hollow shaft is welded to a short Double D shaft that is attached to the lower U joint. Gene