1998 Ford windstar
Spark plug gap
Depends on what plugs you are using an engine. Most cases are .040, with the 3.0L engine. .054 is you have the 3.8L engine and what plugs you are using.
Google it for a correct answer using your vehicle year and engine size. Also this information may be on a sticker on the bottom side of the hood or on the radiator support.
If your doing it right you should be using single or double platinum spark plugs and in that case they are preset from the factory and do not require resetting the gap, doing so would damage the plug.