John,
Regarding the transmission, if the gears and bearings look good, you have a great start. That tranny (GTK-134) has no synchros so if the gear teeth are not obviously worn that is a good sign that it was used by someone who knew how to shift. Check the external case for broken mounting ears (the two at the top). While I am thinking about mounting the tranny, the bottom two bolts mount into the case so be sure to use sealant on the threads on assembly or you will end up with a slow drip.
The bosses cast into the case to mount the parking brake and pedal assembly also need to be examined. They are tapped for the mounting bolts but bottom out. If you use too long of bolts you will break off the bosses. So be sure someone else has not broken them and be sure your mounting bolts are not overly long.
Get your self an repair manual or look up on line (Old Online Chevy Manual, Keith Hardy's site). The only measurement necessary to reassemble is the gap between the cluster gear and case (0.015 to 0.045 inch, I think going on memory). If you decide to disassemble the shift tower, you can put sealant on the ends of the shift rails, another place these trannys leak oil.
Good luck and let us know how it is going,
Kent
