Interesting info. Personally I have never torqued a plug or paid attention to how far it turned after "hand tight". I just tighten them kind of tight but not too tight. The idea of hand tight, then turn a specified amount is a real bogus idea. A plug could stop anywhere due to strength of hand, due to hanging up on threads, due to dirt/grease in hole, due to hot motor, due to anything......and not be at a point called "hand tight". With gasket seal plugs, many companies say hand tighten until gasket touches the head, then 1/2 turn. Good luck with that. I say: Use a socket wrench with one hand only on the head of the wrench until plug is tight. Snug is a good word with gasket seal plugs. Don't have your hand on the handle of the wrench. It is nothing like tightening a bolt. NOT the same.
Any plug will provide a spark if the computer says it fits your application. Does not make any difference what brand. All the brands have various designs and materials. Various "models" of plugs. This "Hot" and "Cold" B.S. has nothing to do with the spark. A spark is a spark. A 216 is not in the world of precision performance plugs. As D.G. Denny says, it's closer to a lawn mower engine.
I always compare the old to the new regarding length of threads and overall stickout in case the counter guy made a mistake. I always do my own searching on all parts. I never accept a part that has been opened, dirty box or repackaged.
If the proper plug is fouling, I would blame the motor.
AC Delco is a R45(s)
