I'm pretty nice to noobs, so I'll bite. You have an AW4 transmission, NP231 transfer case (probably), a Dana 30 front axle, and a Dana 35 rear axle. We really need more information like what "mode" of 4wd you have to tell you transfer case though. A normal operating temp would be 210 degrees although, most of your vintage with no work done to the coolant system run hotter than that.