I used to work at Ford. The truck I would buy would be a 2003 F-350 7.3L with low miles hopefully. If you had seen the problems with the 6.0L(injectors and EGR coolers) and the new 6.4 you would know to stay away from them.
The main reason I would be careful buying a new diesel is all these new...
Ive seen and repaired this before, this is why its very important to measure your tube length with the dipstick and not cut it much longer than the stick. Everytime this has happened Id try to yank on it, and about 1/5 times it would come out. What usually happened was the tube would get caught...