I had an 06 Megacab 5.9 manual that needed nothing in 225K miles other than U-Joints. I did upgrade the clutch after I added some power, the next was a 2014 Megacab with a 6.7 manual that I upgraded the clutch in after deleting it and adding power, that truck also needed a turbo actuator at 200K, I traded that truck in on a 2020 HO with the Aisin last year. So for the 2020 is dead stock with 40K miles on it so far and it's so good as is I don't plan on doing much else than driving it. I have pulled a 24ft GN with a 45HP tractor and attachments, a 20ft enclosed and a 42ft toy hauler around with all of them. I always hear about the bad ones and believe they are out there, but I am very impressed with them as working/pulling trucks. Even stock they all would get down the road much faster than I'd feel comfortable towing.
