Tire size? height? what kinda wheelin? Abuse level of wheelin?
I think most guys would say a Dana 44 mildly built will hold up to about a38.5" tire with some mild abuse (a lot of variables here though).
If you're looking at larger tires, or wanna beat the piss out of it, I think you're going to want to plan on a Dana 60.
Sky offroad manufacturing makes kits for trucks like yours...give them a look. I bought just a front crossmember from them and built everything based around that.
Something else to research is a lot of guys are using 52" springs for the fronts (prolly the springs you currently have out back).
Steering for full-sizers is not something I'm familiar with, so I'll let someone else fill you in there.
But the key is start reading! There's always way more involved than you plan for. Pirate4x4's Chevy section has some very relevant builds for you to have a look through.
Good luck!