Good deal!
I started to look at the 1967 4wd production numbers and seen how few of that year were made to start with, and can't help but wonder how many are still around after 50+ years.
Thanks for the pictures, it definitely helps clarify, plus I had no idea GM made that setup for 67 specific, my memory kept telling me all SM420 were 2wd; I learned something new!
It is definitely cool to try to keep it as original as possible, and sounds like you've got good leads on getting the transmission checked off the list.
Here's a link to some production numbers if you haven't come across it already, it's kind of fun to look through.
http://67-72chevytrucks.com/vboard/s...d.php?t=104816