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recent thread about spark plugs. I'm looking into replacing mine again very soon. I'm currently running Motorcraft AWSF-32PP with about 60K on them, so it's time. I know Autolite APP764 is a good replacement, but in the linked thread Big Jim was talking about Autolite XP104. Has anyone tried these, and with what results?
A couple points of interest:
XP104 is the same heat range as APP104. What's the difference between the APP104 and the APP764?
According to partsamerica.com and autolite.com the APP104 will fit this engine at .054 gap. However, if you cruise over to sparkplugs.com, the XP104 is not listed for the Contour, or anything with a Duratec V6. They only list APP764 for Autolite plugs.
Please discuss.