Thanks for the post. I've been on vacation for a week, so now is my first opportunity to T/S this further. What Motorcraft/Autolite plugs (Motorcraft pn# 4112 or Autolite pn# APP5344) are the 'preferred" plug? I realize platinum is the answer (both I listed are plat); I am looking for a specific change in heat range to the stock plugs that others have found is a benefit.
tia - Bill
