need help with id transfer case tag

[1969 GMC]

Originally Posted by 72timemachine

Finally, how do you understand what the round id tag on the transfer case means, the one in the picture is out of an s 10 but they all seem similar.

Thanks for any schooling help.

That is the newer NP tag. At the very top, it says "231 C" that is your model.
"11 89" is, I'm guessing, the build date. The "2 72" is the low range ratio (2.72:1). The other numbers may be a serial #, I am not sure about those.

The tag on my NP205's is different than pictured, it is on the edge of the pto cover, but it pretty much says the same things.

edit: if your friend's truck is a K30 1 ton, then it will either have th400/np205 or sm465/np205, both will have direct 32 spline couplings (no drive sleeve). they are worth a little more if and/or when you want to sell.