The things that will usually get you is a fuel related thing, tires or an electrical demon.
If you have things pretty well sorted out, just take the tools with you, along with some emergency supplies.
My last long trip in my truck I had an intermittent electrical issue that I wasn't convinced that I had repaired. I stopped at a store on my return trip and bought some electrical wire and connecters... I had taken all my tools with me. It showed up again and I had to wire a fix to get me home.
Sounds like you've already gone through the truck and replaced the usual culprits, so I say pack up and go for it.
-W
