62 short step:
I have done a power steering conversion on a few '64-'66 Chevy K10 trucks. I used a conversion kit similar to the REZ Engineering unit, that I fabricate myself, specific to the K10 frame rail contour.
With regards to the gear box, I use a '68-'86 Saginaw, quick ratio, three turn gear box. Pull the gear box, pump, brackets, brackets, hoses, pulleys and hardware from a '68-'86 Chevy truck, equipped with the same engine type as your truck, i.e. V-8 or straight six. Sometime in the 80's the threads on the box, pump and hose changed from SAE to Metric. It doesn't matter which you use unless you have a pump with SAE threads and a box with Metric threads. This can be handled, as well, but it is inconvenient.
In any event, good luck with your project. You can send me a PM for additional information about this conversion.
Tony