Should I replace my plugs?

[Jackpine]

Here's one "how-to": Sparkplug Change for 2004-2008 5.4 3V-Step by Step - F150online Forums

And another: Changed My Spark Plugs Today/ Writeup - F150online Forums

And yet another: Spark Plug Change on 2004-Early 2008 5.4 3V - F150online Forums

And finally, a technique when things go wrong: New method to extract porcelain from broken spark plugs - F150online Forums

I believe Ford is now recommending a plug change at 70-75K, rather than the old 100K, so you're about due. The BIG caution is "patience", and a cold engine as I recall (I did not read through those threads before posting and am working from what little memory I still have).

And, I believe, the important place for the anti-seize is on the porcelain nose of the plug, not just the threads, because that's where the carbon build-up causes them to bind (and break).

Good luck!

- Jack