I put the 4.7 set into my 85 4Runner and really enjoyed the difference that it made.
I would just go into 4Hi when wanting to do faster easy stuff and drop into 4Lo when wanting to crawl through stuff.
I say go 4.7 and don't look back. I am getting a Tcase setup next week for my stock 85. It won't be so stock anymore. I also won't be cooking clutch on the trail as said above! <img src="/forums/images/graemlins/smile.gif" alt="" />

1985 SR5 4Runner
eLocked with Carter Lock
4.7:1 single case
Davez Offroad twin stick