Certainly looks that way to me. Post some pictures if you can interested to see the nature of the failure. The oil still seems like it go quite a bit more especially with the base number
Agreed. It took 1qt of makeup at around 9600mi. The oil seems to be wearing extremely well. I don't believe this to be an oil related failure. I do not know any history before ~253k. I am wondering if it got studded because of a head gasket failure pushing coolant into the oil and compromising a bearing. I'm hoping it is a cam bearing. The turbocharger oil supply is off of one of the cam bearings. My theory is (if it is a cam bearing) that when the oil got hot towing it just couldn't provide the necessary lubrication as that has been seen more than once on the duramax platform.
Posting pictures is no problem, I fully intend on tearing it down and repairing it/slight upgrades suited to the nature of towing/longevity (better oil cooler, better piston cooling nozzles, more oil pump flow, upgraded bearings etc).