fs: 68 dart
Short of the thing tossing a rod or eating the trans/rear diff..what couldn't you fix on the side of the road? Bring a ballast resistor, some tools, and enjoy the adventure. I plan on doing something very similar in the near future.
Here are some suggestions to be prepared:
Ignition system. I had an almost brand new orange box go Tango Unform on me. It was just down the block from my house too! No warrenty on it.
(But my junk yard orange box that I replaced it with is still running.)
I always carry an extra one too in my everyday "emergency kit" with jumpers and everthing else.
Fuel pump: New fuels are rough on old rubber to begin with but a fuel pump is an easy fix if you carry one.
Starter failure. I carried an extra starter across country. They don't take much room, but are a little extra weight. And if you need on in the motel parking lot it might be worth it.
Fuel system failure. This is a real one. (Take extra filters incase crud comes out of the tank and clogs up the filter).
Other than that, relax and enjoy the drive across country in an old Mopar.
I would and have done it.
And this looks like a car that's worth it. I could fly out and get it.
If I had the time.......................