There was a power steering setup available for the 60-66 medium duty trucks. Most likely you'd have to try to find one and rebuild it.
It was a power ram type of system, I saw one here locally a few years ago on a diesel wrecker (a 64). When the power ram gets old, the system leaks badly - so you would have to replace all the seals.
I'd call to a medium duty wrecking yard and see if you could come up with one. I doubt that you would ever find one on an old farm truck - that was an expensive option for those farmers to pay for - so they usually didn't get it. Expect to find it on more commercial vehicles.
It MAY be possible to use a power recirculating ball steering gear from a later truck (67-72, 73-87). I don't know enough about the larger trucks to say if it will work or not. The 60-66 C,K-10,20,30 trucks can use a recirculating ball power steering gear from a later 73-87 truck with an extension plate (the c-10 frame wasn't tall enough to mount the recirc gear, the adapter plate allows you to mount it on the shorter frame). The C-50 frame is quite a bit taller, so you may not have any trouble.
It's up to you whether it is important enough for you to add.
