I am using the Edelbrock recommended plug. Champion RC12YC's

what should I get as far as plugs to change how hot the ignition gets the engine? I’m using pump gas with a 455ci and w30 style cam. Holley Sniper Quadrajet with timing control

 

comp ratio? And not what you think it is but what it really is.

 

I run NGK V-Powers. Be careful where you buy. Many companies (looking at you, Summit) will ship plugs pulled from a bulk carton, and send them loose, in a plastic bag. I pay a couple dollars more at the local, independent Carquest to have the security blanket of individual packaging.

 

^^^^^

 

Not sure if this is what you mean by your question but spark plug heat range has absolutely nothing to do with engine operating temperature.

 

Autolite 3924

 

But that is not going to affect the temperature that the engine runs at, which I think is what he is asking.