I’m not sure I trust the diesel forums for older engines. It seems the only people left with the old ones either have no issues, or just got a bad one and are trying to figure them out. If you go read the 6.4 forum now, I should have already replaced most of my engine a couple of times at 150K miles. My guess is the Chevy forums are similar. From what I’ve been able to gather, bad oil and no additives are rough on the injectors. From what I’ve been able to gather, some people have continuous issues with their injectors and others have no issues.
I’ve been told my 4.6 in my Explorer should go at least 400K miles from a mechanic who does servicing for a limo company in the Seattle area. He also is a fan of the 6.4 diesel which is in Fedex trucks he services. Yep, he knows DPFs are ****, but otherwise, they’ve had no problems keeping them running any more than other diesel engines. I know ... impossible, right?