Your transfer case has Delco III fluid in it, I believe a Chilton manual instructs you to change your fluid at first oil change, which obviously has come and gone for you. Then every 60,000 miles. I would maintain the same with your tranny.
<font face="Comic Sans MS">For fluids, I'd recommend Mobil 1 synthetic. Seems to work very good, for me at least, in my older T case and differentials. If you're where it gets cold, I'd especially recommend synthetic. Flows way better than dinosaur juice in the cold. May notice a little bit of leaking though if the seals are older. I didn't see a problem on mine and mine are from 1985.</font>
<font face="Comic Sans MS">Dinosaur juice is just the way I tend to refer to conventional base (fossil fuel based) products, like oil and gear lube. I sometimes write things that I know because I say, but then forget that everybody isn't inside my mind to know what I'm thinking (which is typically a good thing that they can't see those items [img]/wwwthreads_images/icons/laugh.gif[/img] [img]/wwwthreads_images/icons/wink.gif[/img]) </font>