My '97 7.3 truck would die on the road, then re-start after coasting to a stop. It was the CPS (crankshaft or camshaft position sensor, forget which one was being sensed). It was replaced for free by the dealer under recall and never had the problem again.
Even without the free repair, it wouldn't have been much money or difficult to install on the 7.3. The dealer told me the part is under like $150. I hear of guys carrying a spare CPS in their glove box and changing them out on the side of the road in a few minutes with minimal tools. I never investigated it myself.
I didn't know the 6.0 had that problem too. Our '05 6.0 never did that.
Another thing you can check is low battery voltage. If the voltage is too low, the truck wont start because of the fuel injection or glow plug system.