What you want is simple and reliable, more than super built. Is it fuel injected? If not, that's the first order of business (a stock TBI350 is better for overlanding than a carbed 383). I would use 3/4-ton drivetrain, unless you will step to bigger tires later. Unless you already have 4.56 or 4.88 gears, you'll need to make this decision now, so you don't spend money on axles you'll be taking out (rear 10-bolt is a bad idea). You definitely need O/D, but a 700R-4 is fine to keep if it's good. Likewise, if you have a good NP208, that's fine to keep. For DD, road trips and overlanding, you want a good ride, some suspension travel and basic creature comforts. Stock suspension is soft, but the off-road ride is bad because there's no uptravel and you can't run a shock with much travel. There is lots to read here about springs, SO DO YOUR READING. Using the softest lift springs available is maybe borderline, definitely not max comfort. So many have asked these questions before, so research and come back with more specific questions, since there is nothing special about these goals.
