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Old 08-18-2010, 05:09 PM
Bobcat Bobcat is offline
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Join Date: Apr 2007
Cobra Make, Engine: # 757 ERA 427 SC , 482 Al. big block
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The only problem I`ve had with the Autolites is the threads sometimes look like crap . Kinda afraid they might hurt the aluminum head . I just bought some NGK BKR6E plugs that are equivalent to the Autolite 3923 plugs and the threads look a whole lot better . The AR 3923 heat range works ok for me ..... but I suggest you err on the side of caution , or rather colder , than destroy an engine . You can go hotter later if the 3923`s are too cold .... after all , plugs are cheaper than an engine . What you are looking for is a 14mm plug.
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