Motorcraft SP500, I just bought six and gapped them all down to .053". Use a wire type gauge if you have any. The center electrode is fragile.
My rig is a 1997, the passenger side is difficult, I worked through the wheel well, with the fender liner removed.
280,000 miles on engine, 100K on the plugs, nine years. Left side all three were worn down to .100"+ (right down to the porcelain), right side much less wear, about .063", although the ground electrode was starting to look pretty manky. Waste spark system I guess. All six were even tan colored, looked really good, and truck ran fine getting 20MPG+. I only pulled them out because of the high mileage. Replacement was scheduled for 100K, the maximum I will run a platinum plug, but after seeing the wear from the waste spark, I will now change to a 50K interval on the left side.
They were all hard to remove, but went back in easily. They still had anti-seize on them. With the nickel plated plug bases I don't think anti-seize is necessary, but honestly I don't know.
That's about all I remember.
Best wishes,
Doc