What spark plug?

ramcharger said
American plugs are colder as the number gets lower.

Japanese plugs such as NGK or ND work the opposite. The higher the number the colder the plug. Not sure how Bosch does it but I'm sure a quick check on the manufactures web site will give you any info you need.

For the record, I'm using Autolite 43's on my last build. If I were using large doses of N2o I would run 42's, stock is 44.

Bbeep71, you are not running enough compression to have to run a colder than stock plug.
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Exactly! I've always run the standard plug, or the hottest plug I can get away with. I like Nippondenso because of the U groove. More sharp edges the better. And if you look closely at Accel plugs you will see they are made by ND (or at least they were years ago). I also had good luck with Autolites in the past.