NGK Spark Plug Stock # 6221 Spark Plug - NGK Standard - 14 mm Thread - 0.370 in Reach - Tapered Seat - Stock Number 6221 - Non-Resistor - Each

NGK Spark Plug Stock # 3901 Spark Plug - NGK Standard - 10 mm Thread - 0.500 in Reach - Gasket Seat - Stock Number 3901 - Resistor - Each

NGK Spark Plug Stock # 6955 Spark Plug - NGK Standard - 10 mm Thread - 0.749 in Reach - Gasket Seat - Stock Number 6955 - Resistor - Each

NGK Spark Plug Stock # 4522 Spark Plug - NGK Standard - 14 mm Thread - 0.500 in Reach - Gasket Seat - Stock Number 4522 - Resistor - Each

NGK Spark Plug Stock #7164 Spark Plug - NGK Iridium IX - 14 mm Thread - 0.689 in Reach - Tapered Seat - Stock Number 7164 - Resistor - Each