Based on the number of EcoDiesels out there with 300,000 miles, many of those are stock trucks. We see them quite often in the EcoDiesel facebook groups. It won't be too much long before we start see 300,000-mile trucks pop up in the 3rd gen EcoDiesel as well. As of right now, most of the 3rd gen high mileage trucks are in that that 200,000 - 250,000-mile range. So far, most of those have been stock tucks.
The point I'm trying to make is that stock trucks vs tuned trucks/Jeeps are doing fine. The issue with a stock truck/Jeep is the emissions. Eventually, the DEF pump, sensors, EGR cooler, DPF, etc. will need to be replaced, but the engine itself does pretty well considering the EcoDiesel has a B10 service life of 150,000 miles.