Delvac 1300 Super isn't synthetic. I used Mobil-1 in my other gasoline trucks and believe it was the best on the market. Mobil-1 doesn't meet the API spec. for the 6.0.

The Delvac is available in 5-gallon and 55-gallon containers. I called the local Exxon-Mobil distributor and got some prices. I was amazed to find it was cheaper at NAPA in one-gallon jugs than the 5-gallon pails, and I'd really rather the 1-gallons jugs because they are easier to handle and dispose of.

Shell Rotella-T is highly recommended too and I probably would have used it except my parts store was out of it when I needed to do my first change. I'll stick with the Mobil since that's what I started with. I don't think I'd consider any other oil than these two, but I do know Royal Purple (spelling?) makes a synthetic that meets the API specification. It expensive though.

NAPA sells the Mobil Delvac 1300 Super for 6.49/gallon and the filter for 22.99. Be sure you've got a drain pan big enough for all that oil!

About the fuel filter; there are two of them. One on top of the engine and another mounted on the frame beneath the driver. The scheduled maint. calls for both of them to be replaced every 15K miles. I need to pick up a pair and keep them in my truck... something every wise diesel owner should do.