I use 0.054" For those of you who still have your coil covers it states on the emmissions label that the gap range is 0.052-0.056". I don't know why so many reference manuals state a smaller gap, because every emmissions label on a 5.0 i've seen states the 0.052-0.056 gap range. I'm talking about 87-93's specifically. Unsure on the early cars
