Im just talking from my personal experience. I have heard over and over that the emmisions will destroy a 6.7. You have to delete it or the motor wont last. I have heard of tons of people having issues with deleted trucks due to the extra power, but i have never know someone who have a stock 6.7 blow the motor. Yes i have seen turbos go bad, egrs, and dpf clog up but never a stock 6.7 motor itself have issues. I have personal known 3 diff 5.9 trucks that have thrown rods out the side of the block. So is a stock 6.7 really all that unreliable? I want yalls real world experience, not just bs opinions.

 

the stock engines are great. The delete is fine but If you tune it, raising the boost...it will eventually need headgaskets. Most of the problems I have seen have been excessively idled trucks that cause egr cooler, dpf problems. people keep driving them instead of repairing and then they have big dollar repairs.