Shot in the dark - Explain my transfer case

[dubya]

Hi,

I know this is a bold shot in the dark, but can you help me identify my transfer case?

I have a '72, K20, 350/th350, 8-bolt wheels with 9/16" studs.

I'm not currently able to look at my transfer to tell, but can you explain some differences in original transfer cases available? This is so when I get home, I can say "Yeah, that's what they were talk'n about" :-)

TIA,
W