Help me make sense of this (1965 4x4)

[350TacoZilla]

Personally I like everything about the SM420 except for the divorced transfer case setup with the 4x4's. Companies like novak make conversions to put a transfer case straight on them but its $$$ and makes for a rather short front driveshaft, personally I would either have a local machine shop open up the bellhousing or turn down the retainer on the SM465. A SM465\NP205 is the old standby for strength but a np208 is still a good case as long as chain isn't stretched from abuse over the years.

On the factory 4x4 thing the vin will tell you.
K= 4wd
C= 2wd