Two options that I know of, but I'm not sure if the first still exists. Used to be you could by an assist kit, it was a pump and a cylinder that clamped onto the steering linkage. It would add some "help" to your manual steering. Second, there was an article in Classic Truck mag (I think, it's at home). Described how to put in the power steering out of a 67-72 model. Looked like a good setup.
