According to the online Ford parts listing there are 2 engines available in my year 2004, the engine is known as either romeo or windsor, its a 4.6 s'cab built around Sept o4, can I tell from the engine number ?

 

Check the 8th digit of the VIN number of the truck (either door label or windshield plate).

Romeo engine has a code of "W" (yes, really) and Windsor is "6".

Also other diffs in number of valve/cam cover bolts.

quick reference article: http://findarticles.com/p/articles/m...05/ai_n8791824

George