Motorcraft Glowplugs ZD-12 03-04 6.0L Powerstroke 

In 2004, the combustion chamber on the piston has been modified (updated bowl design). Due to the design change of the piston, the glow plug has been made shorter by 1.2 mm. If the longer glow plugs are installed into an engine with updated pistons, glow plug to piston contact will result, ending in potential catostrophic engine failure. 

These are genuine Motorcraft glow plugs, beware of cheap knock-offs that tend to swell and break off into your cylinders. Please adjust your quantity as these are priced per glow plug and you will need 8 if replacing all of them.

Fitment: Before 9/22/03 6.0L Powerstroke