My general kit of stuff for a road trip would include (in order of importance):

Acceptable tires including a spare or two if the mounted tires are questionable.
Extra of all important fluids
oil, antifreeze/water,gasoline, brake fluid, gear lube
fan belt
fuel pump and inline filter...known to be good. Especially important if the car has sat for a while.
distibutor..complete with properly adjusted points, cap, rotor, wires
some spare wire (used for electical purposes or hanging a muffler if need be)
assortment of tools to change/repair any of above including the basics such as duct tape.

When driving, keep a close ear for potential problems, and keep 'er down to a respectable 95mph or so.

The more prepared you are, the less likely Murphy's Law will come into play...which is one of said laws in and of itself I think.

Good luck! You shouldn't have any problems if the car is in good order.

-Matt