I'm not surprised..He used the truck not unlike a semi. Mileage like this is not uncommon for over-the-road trucks. The owner also isn't a douche bag & knows how to take care of the equipment that makes him money.
More impressive was a story in MMFF or 5.0 about their 91ish fox body that at the time(1999) had 500K on it with the original drivetrain.