Not load bearing wall at all. I put up a general handyman / small remodeling job up on craigslist and I've received something like 25 inquiries thus...
I could be wrong, but I thought there were basically 2 different transfer cases used in that time frame - NP 203 Full time 4wd or the NP205 part time...
I'm reasonably sure (my Suburban is out and about right now) that the unattached fitting is for an optional engine oil cooler. Replacement radiators...
'98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
'92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
"My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World