Compare Maximum number of 4 items selected Representative Image Champion Racing Spark Plug - 656 Part #: 656 Line: CHP Champion Racing Spark Plug Manufacturer's Defect Warranty Seat: Flat Thread Size: M10 Heat Range: 53 Hex Size (mm): 16mm Thread Reach (in): 0.750 Inch Resistor Plug: No Center Electrode Tip Material: Nickel-Copper Alloy Ground Electrode Tip Material: Nickel Show More Show Less