Many people come to me and say, "Hey, how do you add power steering to a Transtar?"
I don't know, but here is how mine was done, before I purchased the truck:
These are the two bolts that mount the unit. (Looking from "outside" the frame.)
Some day, I'll replace the washers with a better looking spacer, about an inch long.
I'm told this is a Saginaw unit, from a Chevy.
I'm embarrassed for you to see my leaks, but I'll address the issue soon.
Hope this helps. I'm told the job on this truck was made easier because it already had a GM steering column in it. I suppose that might mean the splines are different, I'm not sure.