Just an update. I'm back in Afghanistan and the truck was put in the shop about May 2nd. Due to slow working policies with my aftermarket warranty company, the truck should be finished today and my wife will go to pick it up.
Shortly after posting, I noticed a good deal of oil leaking from the front crank seal or that area. I immediately drove it to the nearest dealership despite the fact that I was 2 hours from home with a loaded horse trailer. (Fortunately, I had access to another 3/4 truck to get home.)
Compression tests showed a drop of 2% in the number 2 cylinder and a 3% in the number 8 cylinder. The stealership said that I would probably need a new motor because of the "blow-by" in those two cylinders. I asked if broken or worn rockers could cause the increased pressure in the cylinders since less exhaust was allowed to be expelled. I also told them that I had heard of this problem in 6.4's. They assured me that there were no known problems and that it was unlikely that the rockers were the problem.
After authorizing the tear down (as per the warranty company's policy), I knew I was possibly in for a repair bill in the neighborhood of $2500-$3000 if it turned out to be something preventable. Ford dealership calls the wife one day and says, get this, the rockers were worn seriously on the number 2 and 8 cylinders.
About a week goes by while the warranty inspected goes to evaluate the situation and make a determination. Good news, they will pay for the majority of the bill. I am still paying about $1200 that covers a few gaskets, hoses, and labor for those items that Ford "suggested" that I go ahead and change out while they were in there.
I asked the dealership to save me a sample of the oil so I can have an OA done. I suspect that there will be some revealing numbers that will explain my problems.
Do y'all believe that doing a DPF delete will help eliminate, or at least reduce the probability of, this problem in the future? Even though my extended warranty is still good, I feel that it may be worth it to go ahead and do it.