(8) 4091 - Pre-gapped Power Spark Plugs - NGK V Power Resistor - Shell - Thread Size: 14mm - Thread Pitch: 1.25mm - Seat Type: Gasket - Resistor: No - Reach: 19mm (3/4") - Hex Size: 5/8" (16mm) - Terminal Type: Solid - Overall Height: ISO - Gap: .020" (0.5mm) Center Electrode - Material: Nickel - Type: V-Cut - Size: 2.5mm - Projection: Non-Projected Ground Electrode - Material: Nickel - Type: Standard - Torque Specs: Cast Iron: 18-25.3 lb. ft. Aluminum: 18-21.6 lb. ft. - Brand: NGK - Heat Range: 7