Fuel system is has issues on these trucks as well. This will fix a lot of it http://www.xtremediesel.com/bd-power-1050316-flow-max-lift-pump.aspx
http://www.riffraffdiesel.com/riffraff-diesel-high-flow-banjo-bolt-6-0l-6-4l/
They also like fresh oil.
Coolant filter is another must.
DPF delete + EGR ASAP
That fuel system sometimes fails at stock levels. Have lived through a few stock fuel systems fail on stock trucks. I can tell you it sucks. One of them it that failed ended up taking out the motor as well. One of the trucks had the high pressure pump fail and the ford tech that replaced it messed up and sent **** to the injectors. Ford had to pay for a new pump and 8 injectors.