What's the best way to convert from manual to power steering?

[saxart]

I'm sick of the crappy manual steering in my '70 LB. Next summer I plan on swapping out the 235's for something wider, this means the steering is only going to get worse, so it's time to pony up and put power steering on Old Roy.

What's the best (cheapest) way to do this? I see online vendors selling all NEW parts, and then there are guys selling used power steering set ups as well. What's the best way to proceed here? My truck is a somewhat beat up original farm truck, so I'm not overly concerned with a beautiful looking set up, just something that functions well.

Also, my understanding is that the pitman arm needs to be swapped out? Will I need to swap out anything else? (This truck has the original 6-lug front end with drum brakes) The engine in this truck is a 350 SB that was swapped out from a later model car, so it has a crank pulley with an extra groove. I'm assuming that groove can drive the power steering?

As you can tell, I'm a total noob to the whole power steering thing, so any thoughts you have are greatly appreciated.