I used a power steering box that fits most mid 70's pickups. I bought a "reman" from Advance Auto. I used the "kit" from Classic Parts that has the steering arm, adjustable drag link and bolts, bracket and bushings to attach the steering box. The kit also came with some good instructions....and I bought the "D" shaft and two universals from the local hot rod shop.(Southern Rod)
The "kit" suggested a pitman arm from a Malibu or monte carlo I think it was. A lot of the GM pitman arms are the same...about 5" I think. I happened to have an old 69 Buick Skylark steering box that I used the pitman arm off of and used the steering box as my "core" for the reman.
I have the numbers ect of what I used/bought so if I can help send me a PM with what you need.
....I'll also add that the new power steering pump is not that expensive and IF you decide to go serpentine belt using brackets off the S-10 V6 (4.3 I think, I used a 1989)) you'll want to go ahead and put a new power steering pump on as the pump can be a little hard to get off once you put it on with those brackets. No big deal though. You can buy the high pressure line and a regular rubber transmission line will work for a return.
OH....I did use a steering column out of a 68 pickup. I wanted it because it had the turn signal and the automatic shift column. It bolts right in and I did not have to cut it off. I did take it apart and put new bearings in it, those pics in photobucket too, and used a '58 Impala steering wheel for the final touch. I liked it also because it is a slim column and I used the original switch key location. I don't like the fat column's with the key in the column. If you want to have TILT then look for an earlier model Chevy Van as it is the right length, around 30 or 31", and it is a slim column too as it does not have the key in column.
Hope some of this helps.
EDIT: this is NOT, I repeat, NOT the kit I used but if you plan to use your old column this is some good reading to get you warmed up.
http://www.classicperform.com/tech_articles/Power-Steering-Trucks/Power-Steering-Trucks.htmAnd as noted in this write up the shock will have to be "leaned" back the other way. To do that I checked the angle of the shock and when leaning the shock back toward the door I used the same angle, drilled holes and bolted it on. AND, I moved the shock on the passenger side back too. This way you just switch the bottom shock brackets side to side and they are oriented correctly!
I have the directions I used some where around here. If I can find them I'll give you a shout.
