Need 1 ton 2x4 to 4x4 conversion advice

[monolith]

Just got a 65 GMC 1 ton panel and I need some advice on how to convert it to 4x4 eventually. My goals are: heavy duty and bulletproof- ultra reliable for back country travel- I won't be rock crawling or mud bogging- I just need a stable overland rig. I'd ultimately like to convert it to diesel- likely a chevy 6.5 turbo for ease of the swap.

Any advice as to axles, steering, transfer cases, adapters, cooling for offroad- I'll probably keep the SM420 that's in it- it shifts like brand new.

Any articles, websites or books I should be reading to study up?

Thanks in advance for your time and advice.