Well, I started this post looking for tips. Got a lot of good ones. Now I'll give one back: If the truck can't make it from Golden to Boulder because it is overheating, you probably don't want it.
Last time I bought a car that was overheating it was my 1986 Celica. I thought it was probably something simple that I could fix. Turned out to be a cracked engine block.
I'm gonna pass on this one!