We have a young family in our church who started their deputation travels around the country raising the support they would need on the mission field. As they were getting ready they needed a 5ver to haul for their family and a truck to haul it. He asked me one day about things to avoid and I told him to not walk away from a truck that had the 6.0 in it - run from it.
They had a person in a dealership offer them a "deal" on a 05(?) truck and a pretty nice 5ver bunkhouse. This time he didn't ask me, he knew what I'd already told him. In short he bought the combo and an "extended warranty" on the truck, thinking that it would cover things if it blew up.
After three months on the road the motor puked just 75 miles away at a local church. His extended warranty did Help" with the overhaul but it still cost him $3500 out of pocket. I suggested that he take it to a local shop that bullet proofs the 6.0, but he had lots of meetings to get to and decided that he needed to get on the road. 7 months and 60k miles later the motor puked again in Montana in the middle of winter. The warranty company stepped up and covered all but $2000 this time and he was back on the road for 13 months in Omaha Ne, the motor puked again. This time with no warranty and facing a $12k bill at a ford dealership, he elected to trade it all in on a Explorer that he would be able to drive for the last month of his time on the road.
Three major pukes in two years of full time RVing. I believe you can never argue a idea with a man who has experience. Our young friends have experience - I wonder what they think of a 6.0 now???