I friend of mine has a 2003 F-250 with the 7.3L Diesel for sale that I am going to look at tomorrow. It has 75,000 miles on it, and I know it has had meticulous care (he is a retired heavy diesel mech...
I own a 2001 7-3 that has 163,000 miles on it. I bought it used with 43,000 miles on it. The motor is the best power plant I have ever owned, the thing with these trucks is that you need to keep your oil and filters changed on a regular basis. That is the lifeblood of these trucks and if you do that it will give you great service. The only things that I have changed is the regular wear items such as tires, wipers ect. Great truck and it pulls my 10,500lb. fiver great.