[BenI]

Ive driven my 914 from FL to CO 5 times now, and have learned MUCH from these experiences! A five hour trip is a bit different from a 24 hour trip, but if something is about to fail, 5 hours could be all it needs. Still, have fun! These cars are great, and parts are relatively easy to come by through chain auto parts stores. My advice is this:
1)Adjust valves before trip
2)Bring tools-sockets, open end wrenches, pliers, jackstands...I have an almost complete tool kit in my trunk.
3)The part(s) that will most likely fail are those that you do not know thier history-everything that Ive had to fix on the road has been a part that I had not repared or replaced yet.

This is not meant to scare you, just some notes from my experience. Good luck! And have fun, because thats what these cars are about.

PS-On the road Ive had a wheel bearing go at the grand canyon, a starter begin to fail, an accelerator diaphram on a Weber fail and I got a dirty gas tank in Eastern Colorado that took me 1000 miles of playing with the ignition system, timing, and carbs (rebuilt both in a motel room due to the pump failing) before realizing that it must be a clogged sock filter in the gas tank. The symptom was that I could only drive a couple hundred miles before the car would lose all power and Id have to wait 6 hours or so before I could move again. These were all exciting experiences that worked out fine in the end!