Can anyone tell me what all i need to do or need to get to change from a turbo 350 trans to a 700r4 on a 76 1/2 ton 4x4 full time (soon to be part time) 400cid? Does it just bolt right up or what? I was told the 700r4 is kind of weak, but then i was told you just got to get the right kind of servows. Any how what i want to do with this pick up is to have a nicer older driver that i can tow a trailer sometimes, hunt with it go wheeling with and get the best fuel mileage possible. Just a good all around pick up. Any good advice out there?

I am looking at doing a similar thing to my 72 Suburban. The first few years of the 700R4 were not very good. I don't know what the problem was but I was told to stay away from the 86 and older model years. 87 and after were better.

Another option to look at since you will be doing some trailering and wheeling is the 4L80E tranny. Yes, it does require some electronic wiring (not exactly sure what that all involves yet). The good thing about this tranny is it is essentially a Turbo 400 with an overdrive and some electronics. It is much more durable than a 700R4 and don't let the electronics scare you. I think it is pretty straight forward.

Advance Adapters has what you need for either swap. The good thing about the 700R4 is it has a 3.06:1 first gear compared to your 2.52:1 first gear (I think that is the correct ratio) plus the overdrive is 0.70:1 compared to the 4L80E which has a 0.75:1 overdrive. Not much difference really. Anyway, check out the links.

http://www.advanceadapters.com
http://www.transmissioncenter.net/4L80E.htm

Good luck to you.