I found this web site and spark plugs that can tell you how your engine is running and what may be going on inside and thought I'd share it with my fellow GSer's
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html
Hey that's really cool! Maybe someone can sticky this. Perfect for helping newbies!
Those plug pics are for leaded fuel go to this site http://www.angelfire.com/fl4/pontiacdude428/Readplugs.html it is excellant i know it states for dragstars but put 2or 300 miles on your plugs to carbon them up a bit then read them /this applies to unleaded fuel