Loss of Power and Intermittent Miss

[tractorman21]

I have a few questions for some of the experts on this site:

I have an 2008 F-350 with the 6.4 Diesel engine and I am having problems with the motor running smoothly and there is also a loss in power.
This is a work truck and somewhere along the line, some contaminated diesel fuel was put into the tank. The truck started acting really bad and was taken to the local Ford dealer. They replaced both fuel filters, but the tank wasn't drained for whatever reason. The truck ran ok for about a half a day after picking it up from the dealer. Now the truck doesn't have much power and there is a noticeable miss in the engine. The miss gets worse as the rpms go up.
The dealer has the truck again and now they saying that the rocker arms are wore out that is where the miss is coming from. The motor has 150,000 miles on it and before the bad fuel deal, it ran very well.
I need this truck for work and I am not sure about spending the $ 2,000.00 or more dollars on rocker arms.

Anyone have any thoughts on this problem?

Thanks for any help, or advice.

 

[01yellerCobra]

If the tank wasn't drained then you're right back at square one. New filters are pointless if you're running the same bad fuel through them. Get your truck back from that dealer. Drain your tank and put fresh fuel along with new filters.