I believe one-ton trucks and diesels came with Hydroboost. I Bought my hydroboost unit from a member here who parted it off of a 1-ton with a 454, but then I had to get a pump, which I pulled from a 350 in a 1-ton, and when I needed new lines, I told the parts guy they were from an '85 diesel. I saw some different configurations of hydroboost setups at the junkyard, some pumps had two ports for return lines, one from the boost unit, one from the steering box, others had a single return line to the pump, with the return from the unit t-ing into the return from the steering box. I think if you get a complete setup, pump and boost unit from the same vehucle, you should be good to go. Get the lines too, even if you dont end up using them in favor of new ones, you can match the new ones to the old ones at the parts store to make sure you are getting the right ones. One thing to remember, is when you get the boost unit, get the rod/linkage that goes to the brake pedal, as I am pretty sure they are a different length than a typical vacuum boost unit has. I don't know if the master cylinder's are different, so you might want to grab that too.
