Denso Iridium Racing Spark Plug - 5754 Part #: 5754 Line: DEN Denso Iridium Racing Spark Plug 1 Year Limited Warranty Seat: Gasket Thread Size: M14 Heat Range: 27 Hex Size (mm): 21mm Preset Gap (mm): 1.1mm Center Electrode Core Material: Copper Center Electrode Tip Material: Iridium Approximate Resistor Value (Ohm): 5000 Ohm Thread Reach (mm): 21mm Metallurgy: Iridium Show More Show Less