jake,
here are a couple articles on spark plug heat ranges and other info.

http://www.ngksparkplugs.com/techinfo/spark_plugs/overviewp2.asp

http://www.carcraft.com/techarticles/spark_plugs_tips/index.html

i always heard of different heat ranges, but never really paid much attention to them.

but from what i was told by the guy at my local speed shop, is that the higher performance an engine you have, say radical cam, high compression, power adder such as turbo, blower, or nitrous, thats when you want a "colder" spark plug.

my original champions were burning all the fuel off them, but seemed to be too "hot", so that is why i went one step "colder".

i will drive it a few hundred miles, pull a few plugs, and see how they look. if they are still burning all the fuel off them, showing no signs of fouling up, then i am good, since i now have no pinging under load.

hope this helps, but i am by no means an expert on this subject.

leonard

1957 Chevy 3100 1/2-Ton
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