I've owned 2, both had major work done, an 03 & 06, if they have money spent on them, i.e., head studs, egr delete, oil cooler, they can be good, but they are hit and miss. And for those that don't know, the motors changed for emissions reasons, not because of trouble. The scrapped the 7.3 because of emissions standards, increased the stroke in the 6.0 to 6.4 for emissions standards, then when to the 6.7, after scrapping Navistar. All 3 changed their motors, the 5.9 cummins met the first set of standards, it's didn't meet the next set, that's when Cummins went to the 6.7L.