The transmission from a FJ80 will not work in a FJ62.
The FJ80's were full time 4WD and use a different transfer case that the FJ62's.
The output shaft on the FJ80 tranny is different. The 62's goes all the way through and has a nut on the back of the transfer case while the output shaft on the 80's only goes into the input gear on the transfer case.
I tell you this from experience!!! Wanna buy a tranny from a FJ80!
All that being said, if you are at all mechanical you can rebuild it yourself.
I just did mine about 3 months ago and it's working fine. (I'm a radio tech, not a mechanic!!) The rebuild kits are fairly inexpensive (about $250) and with all the othere parts I replaced I ended up at around $2K. I splurged and bout an upgraded valve body from Rodney at Extreme Transmissions and that was about $800.
Check out this trhead to see what is involved in rebuilding it;
http://forum.ih8mud.com/80-series-te...nic-style.html. It is an excellent run down of his rebuild.