2008 F350 Dually

The 6.4 are notorious for rocker arm wear due to fuel dilution (this wear is usually excellerated by the F450/F550 trucks due to higher rpm operation), errosion of the aluminum front engine cover behind the water pump to the point where antifreeze can get into the engine oil because of the large water pump impeller forcing massive water volume, lower EGR cooler can crack and fill the #8 cylinder with antifreeze and hydrolocking the engine. Because of the above mentioned issues, a catastrophic engine failure can be avoided if the operator frequently checks the fluid levels.

I spent some time talking to my cousin this past Christmas who is a Ford and Cummins certified tech he does not recommend the 6.4.