Have a 2006 Chevy with 160,000 on it. The vast majority of them with a 13,000# plus trailer behind it. Nothing other than routine parts that wear like bushings. It gets a thorough once a year refit with frequent oil changes in between. Can't fault that 6.6L Isuzu at all.
I am partial to a 5.9L Cummins, if only because I have one in my boat, a mid 90s motor, before all of the electronics, so I really can't say anything about the new ones. A marine diesel spends its whole lifetime in effect going uphill. The resistance of the hull going through the water never eases.
There are plenty of Cummins on the water. There are plenty of Isuzus too. Ford? Very rare. That might say something. On the water you don't get out & walk when something goes wrong so reliablity is very important.
