Champion Racing Spark Plug - 264 Part #: 264 Line: CHP Champion Racing Spark Plug Manufacturer's Defect Warranty Seat: Flat Thread Size: M14 Heat Range: 61 Hex Size (mm): 21mm Hex Size (in): 13/16 Inch Preset Gap (in): 0.028 To 0.033 Inch Preset Gap (mm): 0.58mm To 0.71mm Thread Reach (in): 0.375 Inch Resistor Plug: No Center Electrode Tip Material: Nickel Ground Electrode Tip Material: Nickel Metallurgy: Copper Show More Show Less