You'll love the 3.07 first gear, and the OD is butter!
You'll have to move the mount back a bit, shorten the driveshaft, hook up the TV cable to the carb arm, install the lockup switch on the valve body,...that is about it.
<a href="http://www.700r4.com" target="_blank">www.700r4.com</a> is a great site for all kinds of good info.
Oh, about the year - common thought is '86 and up. I had an '85 from an IROC-Z in a little roadster a few years ago, and I felt it was like any other I've had. Go figure.