Noob has Questions

[heavychevy78]

First I'm not a noob when it comes to offroading. I have wheeled jeeps for a few years but made the move to my 78 k10 swb for doors and a heater. It gets a lil cold in GA on the way to PT in the mornings. I am leaving for Iraq soon so I will have money to burn. Here my questions for the experts.

1. I am shooting for a 6 in lift and 37in tires. Do I need custom drive shafts?
2. What gears should I be running for best all round gas milage and torque?
3. GM ZZ4 crate or 383 stroker crate or rebuild the 350 4 bolt main thats in it?
4. I plan to keep my TH350 and 203. Is this a wise choice?
5. If I did trash the 203 will a 205 bolt in? If not whats my best choice?

The rear end is a 12 bolt and front dana 44. Engine is a 350 4 bolt main with a eldebrock intake and 750 carb. I dont know what cam is in it but it does have a real low lopey idle. Right now she sets on 4in springs in the front and blocks in the back with plenty of room for the 33's.

I'm looking to invest about 10 grand when I get home and this will be my daily driver to and from work as well as my wheeler. Any insite would be helpful and opinions are always welcome.