Gear Oil: Cheap-O Rotella Gear Oil 80W-90 from Wall Mart for the first 2K for a break - in , then I will go with Mobil 1
Diffs: Toyota 4.11's bought used from Mark's off Road, They go well with the 5 speed and 33' tires.
Lessons:
1) Use an air impact wrench to get the output flange nuts off.
2) Make a wood cradle for the tranny (Not just 2x4's stacked up)
3) If you are using ramps be prepared to jack up the '60 in order to get the tranny out from under the frame rails.
4) Remove the tail pipe at the exhaust manifold to permit jack clearance
5) Have someone help you put the tranny back in.
6) Have access to or buy a press to get the bearings off for the t-case rebuild.
7) Have access to or buy pilot bearing puller for the t-case rebuild.
8) Have access to or buy a pressure washer (makes cleaning stuff real easy)
9) Have access to or buy 32 and 36MM sockets.
10) Label and bag all parts that come off, you will have many to keep track of.
Take your time and do a good job. I took my tranny and t-case out on a Sat, and supported the motor with a jack stand and a 4x4. Over the following week I rebuilt the t-case after work working 2-3 hours per night. I then put it back in on the following Sunday. NorCalFJ60 came over to help and I could not have done it without him, it was not easy getting the tranny back in on an uneven driveway. it is amazing how people on this forum will come together to help each other out !
By the way, it takes a while to get the tranny to shift from 2nd to 3rd smoothly. You might try to double clutch it.. mine is still a bit wonky and I hear that is common.
HTH
Mark