Thanks HRPC. Have a shot at a used (not rebuilt) 700r4 for $350, may pick it up to put in for the time being. My goal is to actually pull the truck off the road so I can do all the work, both custom and resto, that I want to do. But, If worse comes to worse, I want to be able to drive it if I have to.
My experience level is from 25 years ago. Way back when, I did all of my own work, but never had the opportunity to rebuild a tranny. I'm willing to do anything and never refuse advice or loaned knowledge. I have an OLD chilton's manual, but will be shopping for more, especially for the tranny.
The other item that I just thought about while typing about the used trans is that a friend has a 454 that I might be interested in putting in the truck. My suburban is currently stock, with some serious duty suspension, or an old lift, as it currently sits on 33" with only minor front tire rub if I turn and hit a bump at the same time.
Eventual goal is to lift it about 4", switch up to 35", fix all rust and repaint. Swap front bench for buckets, recover back seat, replace carpet and refresh balance of interior. Engine?? Either remove TBI and all electronics from 350, moving to 4bbl carb. OR, move up to the mentioned 454 with minor improvements to build torque. I'll need the final transmission to be able to handle either engine. Haven't really looked at what final gearing I'll need to run, but I know it'll need to be changed.
For the stronger motor should I just plan to convert to a TH350 or TH400? Could a fully rebuilt 700r4 handle a big block with strong, but not extreme, torque. I'll use the truck for cruising, light mudding and off roading. It will not be a daily driver again.
Believe it or not, when I told my wife the trans had gone, she suggested I find something to drive while I do EVERYTHING I want to do, then put it back on the road, and has now suggested at least three times that I just build a BIG mud truck that'll carry the family through the mud.
Again, thank you for any and all suggestions on parts, processes or for the truck in general. Over the next few weeks I'll be reading all the posts throughout the forum.