off road truck help?

[71blacklighting]

i am thinking of building a truck just to 4 wheel in but i am on a budget i can get a good 4x4 frame from a 79 and a body from a 71 it has a good 350 and a turbo 350 trans but not sure on the transfer case first of all will the auto be a good trans for offroading and how can i tell what kind of transfer case i have. would a bulldog 4 speed be worth a few extra hundred bucks? or is there a better trans. thanks alot guys any responce will be great ill post some pics of the truck when its finished and in action..lol it should be a blast.