Engine V8, Engine Size 7.4L/454 Engine Family Chevy big block Mark IV Trivalent metal plating provides superior anti-corrosion and anti-seizing properties. Corrugated ribs prevent flashover. Pure alumina silicate ceramic insulator, provides superior strength and better heat transfer. Copper core aids in heat removal. Triple seals prevent leakage Sold In 8 Pack 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: 5. Electrode Tip Material: Nickel alloy. Electrode Core Material: Copper. Insulator Type: Non-projected. Spark Plug Thread Size: 14mm. Spark Plug Reach: 0.460 in. Spark Plug Seat Style: Tapered. Wrench Diameter: 5/8 in. Ground Strap Quantity: One.