atf in a transfercase? also rear end and xcase id pls

[67cst]

has anyone ever heard of using atf in a transfer case? my dad just bought a 72 chevy 3/4 ton 4x4 and is just going over everything...he said that the manual says to use atf in certain transfer cases...anyways the code on his xcase is:

1
C-99404
W

the 1 and W are in those places, above the C and below the 9

Also just out curious to the ratio in the rear end, the code off it is:

3934635 i might have a pic of it here if that helps

thanks, Derek