Autolite 3924 or 23?

[70Roadkill]

ive got a 360 magnum engine running eddy heads and and me gasket this head gaskets so I figure I’m in the area of 9.5-9.7 area for compression, running a voodoo cam, knock off air gap and 750 vac sec carb, 8.8 ign wires, etc. was wondering should I go one size colder plug from a autolite 3924 to a 3923 being running more compression that stock

 

[stroked340]

I run 3924's in my 360 with Edelbrock heads gapped at .045 ran the same plug in my 11.9 to 1 416 never an issue always performed well..

 

[fishmens67]

NGK FR6 or FR5.

 

[Dubob]

For heat range pull a plug and see how many threads show heat. Should only be a couple. If more I’d run a colder plug. The engine will tell you what it wants.