I used two U joints with a solid splined shaft in between. It's the lower shaft from BC Broncos. I think the PS box is 13/16" splined shaft, the steering column shaft is 3/4" 36 spline. I turned my steering column shaft into a double D end and used that type of U joint up top. It was as simple as grinding another flat spot on the opposite side of the factory flat spot.
I think there are other ways to get it all hooked up using rag joint, or other options, but that is how I chose to do it.