What do you think of this plug?

slantsixdan said

Don't waste money on high-cost gimmick plugs. Try NGK #ZFR5N extended-nose plug (used on many, many late-model Mopars if it makes your ignorant tech instructor feel all warm and fuzzy about them...or take a more realistic approach and just visually compare the materials and build quality of the NGK to that of the Autolite or Champion.) You'll need a smaller 5/8" plug wrench to install the ZFR5Ns compared to the larger 13/16" wrench used to remove the 65s.

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I totally agree. Spark, being electricity, takes the path of least resistance to ground. Therefore it's not at all possible to fire those fancy multi ground electrode over priced spark plugs. If someone installed them and their car ran better it is only because, 1. it needed new plugs, or 2. they were a closer match in heat range and/or electrode depth to the engines requirements.

I have ran almost every plug made and have had the best luck with NGK's. Last long and don't foul easy. Best part is their cheap. They cost no more than Champions, AC's, or Autolites at the local auto parts store.

As far as the plug in question it looks like your running rich from the soot on the shell. Could be an overly zealous choke, rich idle, or rich at WOT.

Oh and I don't think this has been mentioned but your instructor is an idiot. LOL