On the 3 '67-72 GM C50 trucks I have owned, the PS pump was v belt driven off the crank pulley, the PS hoses went directly to a hydraulic ram assembly that incorporated a spool valve, one end of the ram attached to the tie rod and the other end was bolted to the front beam axle. Movement of the steering gear moved the spool valve which directed hydraulic pressure to the ram, reducing steering effort. Hope this makes sense, this system is as simple as it gets. If a loss of fluid pressure occurs, the steering effort is increased, but manageable. This system would be adaptable to about any straight front axle truck. The '55-57 Chevies had power steering pumps piggy backed on the back of the generator, later Chevies may have had the same system, I expect that the after market restoration houses can supply the special generator with a splined output to drive the special PS pump, big $$$$$ I expect. I don't know when they changed to direct crankshaft driven PS pumps. Crankshaft driven pumps are very common and inexpensive. Corvettes from the mid 50's up used a similar ram system for PS. I don't know if a Corvette PS rebuild kit would work for our purposes or not. Good luck!
