So last spring after seeing vids on youtube about a 5.9 to 6.7 swap I went for it and found a 2010 6.7 from a local auto wreckers. Spent a month dropping it in and on the final day turned the key over only to hear a knock coming from the bottom end. Auto wrecker I bought it from was great and offered a refund or another engine they had on the shelf. I decided to go for the engine. Got the new engine home pulled the injectors to put the 03/04 injectors in but this time decided to bore scope the cylinders first. Luckily I did because 2 cylinders had scoring down them (see pics). SON OF A... Auto wreckers was great about it, came to house personally to pick it up and refund me my cash. Since then Ive been on the hunt for another 6.7 what I found out was there are 2 types of 6.7's Theres a standard 6.7, and a HO (high output) 6.7. Of course now I want the HO one but they seem hard to find as they started making them in 2011.5 -2012 at 350 hp but changed them in 2013--2018 to 385 hp were only available in the 3500 paried with the aisin transmission. Are these HO engines a golden egg and is it really that big of a difference over the standard 6.7? Im I splitting hairs waiting and looking for one of these HO engines? Also are the first gen 6.7's an engine to stay away from? The 2 that I got from the auto wreckers were both first gen's 2010, 2011.