Spark Plugs

As long as you wait till the engine is cool to the touch to begin removing them you shouldn't have any problems with this engine. If by chance you do find a couple plugs that are being stubborn try loosening them a 1/8th to a 1/4 turn then spray some penetrating lubricant into the plug well and let it sit for about 15 minutes and try again. Repeat as neccesary.

If some of the plugs were hard to come out then it will also be a good idea to purchase a spark plug thread chaser. You'll run the chaser down the plug hole to clean the threads and remove any built up carbon or debris. Then install the new plugs BY HAND until seated, (this prevents the cross threading) then rotate them with the wrench another 1/16, or if you have a torque wrench you'll tighten to about 15lb-ft.

Also if you use a high quality plug like an NGK you won't need to use anti-seize because the plug already has a nickel plating thats designed to prevent siezure to the head. In my 99 GT vert I've always used NGK's and had good luck with them. I found some of this info from their website page on plug installation:

http://ngksparkplugs.com/tech_support/spark_plugs/installation/index.asp?mode=nml

-Brandon

NGK seem to work well enough, but also Motorcraft & Autolites are the plugs designed for the engine, hard to beat for longevity. Don't use Bosch!
To add to the above good advice, if you have an airline, slacken the threads 1 turn & then blow the thread wells clean before removing the plugs ,this will stop any debris falling into the cylinders & damaging the engine.

Aeroman said:

NGK seem to work well enough, but also Motorcraft & Autolites are the plugs designed for the engine, hard to beat for longevity. Don't use Bosch!
To add to the above good advice, if you have an airline, slacken the threads 1 turn & then blow the thread wells clean before removing the plugs ,this will stop any debris falling into the cylinders & damaging the engine.

Click to expand...

Good advice on blowing out the plug well.

An interesting point most don't know is that Motorcraft is just a 'Ford' brand (they don't make plugs) that is supplied by NGK, Nippon Denso, and Honeywell (owns the autolite brand).