2000 F-150 4x4 Lariat. I went to the dealer to get new spark plugs, the ones they gave me have more treads. the spark plug is the same size. So my ? is would that make a difference? I'm guessing the new plugs would go in deaper, and since the coil spring still the same size, is it going to make good contact? they told me those are the upgrade plugs. Also I was wondering the way the springs fit on the plugs, they look like the fit is loose, not a snug fit. Any comments appritiated.. thanks in advance....

 

Details like engine and part numbers would be useful....