NGK Standard Series spark plugs are designed for stock replacement applications. These plugs have a hotter spark, which means better combustion and that improves performance, while producing less harmful emissions. Shorty Spark Plug: No. Resistor: Yes. Manufacturer Heat Range: 7. Electrode Tip Material: Nickel alloy. Electrode Core Material: Copper. Insulator Type: Projected. Spark Plug Thread Size: 12mm. Spark Plug Reach: 0.750 in. Spark Plug Seat Style: Gasket. Wrench Diameter: 5/8 in.