Sorry, but I must inject a warning note amid this big ole 7.3 lovefest.
Was getting fuel a couple weeks ago and a guy in a '99 Ford 7.3 PU pulled up on the other side of the island (I know the year of the truck because I asked him).
After a minute I heard some grumbling so I asked if there was a problem. He came around the corner holding the fuel cap, which now was in at least 2 pieces.
He was grumbling because the OEM cap failed and the truck only had 452,000 miles on the odometer.
So I would be very wary. Looks like the weak link associated with the 7.3 engine is the fuel cap. Make sure to check it if you are seriously considering buying the truck.
Tim