i know what the problem is. its a 3.0! what you need to do, is unscrew the radiator cap off, and screw it on to a new 4.0 or better yet, a new truck.
naw, just kidding. it has symptoms of air in the line. try running it on idle for a few minutes to with the rad cap off. i can't remember if there is a purge cap in those years or not.