Today, I changed the spark plugs in my '94 F150 with 302:Found stinking Champion plugs in it!!! they were #RV15YC6, and I replaced them with Autolite #25 from my local hometown parts store that I trust 110% to sell me the correct parts, the Champions looked differentin that the center ceramic was longer than on the new Autolites,truck seeme to run better, can anyone confirm that I've got the correct Autolite # plugs please?? Thanks! Rick

 

there is a sticker under the hood.,prob. around the radiator shroud.or the rail across between rad. and shroud. (or the owners' manual.)

 

You know what....I'll sure check the sticker, but I think it only gives the number of the original MOTORCRAFT plugs, Thanks!

 

The parts store should have a conversion chart where you can cross reference the part numbers. If I remember correctly the cermaic piece indicates the temperature range of the plug. The longer it is the hotter the plug runs. By hotter I mean the less heat it dissipates to the engine through contact with the metal engine head. Hotter plugs tend to cause detonation easier in low compression engines like those normaly found in our trucks.