Two speed rear end in a P/U?!

[Farm_Truck]

Alrighty folks. new to the website and new to the trucks older than '72. (Save for a '55 3100 but that's besides the point.) Anyway. Looking at picking up a '63 C20 with a 4 speed and the 2(71?) small block. It's cheap, and halfway buried in the ground, but mark my words I'm gonna try and get it roadworthy. I know it's probably the least of my worries, but I was wondering if it was possible to stick a two speed rear end from a '58 dump truck under the pickup. It's only got a 4 speed, but it would be the only one around. If it is possible, how hard is it to hook up? Does it need vacuum or positive air pressure? Do I need to change the driveshaft or frame? And, is it possible to change the hubs on them, or would I have to stick with the huge effin tires and rims? Or, would there be a better option for it? Thanks for the help- in advance of course.