A blade "flat" type feeler gage is not the prefered tools to use. A wire type gage is best to measure the gap.
Got a website link to a recommended wire type gauge?
Sounds just a tad more precise than Frank's method. Heheh.
Aircraft engines have aluminum heads and have used spark plug anti-seize for eons. I always use nickle anti-seize on aluminum heads. I have seen plugs seize on aluminum heads - not fun. Make sure you do not get any past the threads. See instructions on link.Is the Motorcraft AGSF-22FM1 gapped to 0.040-0.047 in. still the recommended spark plugs for original unmodified engine? Any problem with using a thin film of Permatex 77124 Nickle anti-seize?
I think the factory torque is 13 lbs and if using anti-seize a reduction to 10 lbs may be appropriate. Please double check the manual for the correct torque setting.
We'd recommend:Is there a better/improved spark plug than the WSM specified Motorcraft AGSF-22FM1?
Virtually all of the no-longer newfangled Platinum tipped plugs have a new Iridium tipped equivalent. I put a set in my truck.We'd recommend:
NGK 3689 TR6IX Iridium IX Spark Plug