What is the correct Motorcraft spark plugs and plug gap 2004 E-250 5.4L Ford cargo van?

The correct Motorcraft spark plugs for a 2004 Ford E-250 5.4L van depend slightly on whether it has the Triton V8 engine (most likely) and any specific service bulletins issued at the time. However, Motorcraft SP-459 (or equivalent) is a very common and usually correct choice.

Crucially, you MUST check your owner's manual or a reliable online parts catalog (like AutoZone, Advance Auto Parts, or Napa Auto Parts) using your VIN number for definitive confirmation. These catalogs will show the correct plugs for your specific vehicle based on its build date and options.

Regarding the gap: The recommended gap for SP-459 plugs is typically 0.052 to 0.056 inches (1.32 to 1.42 mm). However, this is another detail to verify in your owner's manual or parts catalog. Improper gapping can significantly impact performance and engine longevity. It's better to have them gapped professionally by a mechanic if you're uncertain.

Important Note: While you can buy a gap tool to do it yourself, it's easy to damage the electrode. If you're not experienced, a professional gapping is recommended.