Re: Spark plugs for edelbrock performer heads. - 03/17/2012:05 AM
the edelbrock heads use a 5/8" hex, 3/4" reach plug. I've been using autolite 3923, 3924, or 3926; depending on what i'm doing. i'm sure an NGK equivalent would work well.
Re: Spark plugs for edelbrock performer heads. - 03/17/2002:06 AM
Being Alumium heads do you all think you should start with a standard heat of go colder? I was told to run a 5/8 version of the RN12YC but I want Iridum so I went for Denso IQ16TT's that are in the heat range of 12. They have a colder IQ20TT too that is a 9 to10 heat range
Re: Spark plugs for edelbrock performer heads. - 03/17/2007:53 PM
The reason I ask is I have never run aluminum heads on anything except my 2.2's. Someone told me that if the Iron head required a RN12YC that the alumumn would wick too much heat out of that plug so 1 or 2 steps hotter is needed. 1984 Dodge Shelby 2.2 10:1 CR was RN12YC. Mine was a 0.040 over true 11.2:1 CR and I found a RN9YC worked best. 1984 Dodge Rampage 2.2 8.5:1 CR was RN14YC