Welcome, you got one of the last good diesel motors put in a Ford.
My wifes Aunt has a 01 Cummins and it's a dog. The front end was first serviced at 50K miles and it's had two tranny services by 85K miles. I got a chance to run stock to stock against the Cummins in the F250 and was a pretty close race, although at the time the Cummins had 50K miles and the F250 had 200k miles. A few months ago ran the X against the Cummins and same deal, pretty close race. At the time 75K miles on the Cummins and 160K miles on the Excursion.
By comparison the Excursion's front end was first worked on at 165K miles and the tranny has never been touched except to change to syn at 165K. The F250's front end was first worked on at 150K miles and a chip destroyed the original tranny by 83K miles, 239K on truck.