E3 Spark plugs do work

IQ52 said
Hmmm. I have a 600 HP small block going back on the dyno here real soon. We are using the 5672-8 plugs in it right now. I just got my monthly paycheck from Donald and I think I can spring for some E3's.

So we tried the E3 spark plugs today. Gained nothing in peak horsepower. We did however gain 2.5 lb-ft and 2.0 hp average from 3,000 rpm to 6,000 rpm.