JUNKYARD 5.3L SPARK PLUG TEST. HOT PLUGS VS COLD PLUGSWHICH ONE WORKS BETTER? HOW TO TEST SPARK PLUG HEAT RANGE. TESTED DENSO IK16 (HOT PLUG) VS DENSO IK31 (COLD PLUG) ON ALLLALUMINUM, 5.3L L33 EQUIPPED WITH BTR RED HOT CAM, FAST LSXR INTAKE AND LONG TUBES. ALSO TESTED TAPERED SEAT PLUGS VS GASKET SEAT PLUGSDOES IS CHANGE POWER? ONCE AGAIN WE HAVE TO ASKWHEN IT COMES TO IMPROVING LS POWER, SHOULD WE EVEN BE LOOKING AT SPARK PLUGS?