I have an '01 F250 w/ 7.3 and even though it is for sale right now, they are very good engines compared to alot of my friends that have had problems with the 6.0's. I will be looking for an Excursion with a diesel as soon as I sell my F250 so I can keep the same drivetrain but add a little more room for the girls
The thing about all the diesel motors is that they are 300K mile motors that are surrounded by 100K mile parts, like alternators, turbos, wiring, trannies, etc...If you keep any truck for 300K miles be prepared to do a little more than regular maintenance as the parts around the motor are the ones you will be replacing