There is a serious problem with the spark plugs that ford used in their 4.6, 5.4, and 6.8 motors from '97-'07 . The spark plugs are separating when you try to change them. I've been told if you can change them before you get to 60k miles you should be OK. My truck has 62k miles and the mechanic broke off 2 out of 4 yesterday. The only good thing for me is I got a quote before they started work. If ford does it they have a disclaimer stating that any extra work due to the plugs breaking off is the responsibility of the owner. I've heard of people paying in the neighborhood of 2500 dollars to have the heads pulled in order to get the broken plugs out. If you have a mechanic not familiar with this issue, there is a trick to having better success on getting the plugs out. Have them look up the ford service bulletin on this. Just a heads up!
wes