Champion 415-1 Spark Plug, 0.029 to 0.035 in Fill Gap, 0.551 in Thread, 0.813 in Hex, Copper

RN9YC & RN11YC4-32: Resistor plug, 14mm, 3/4 in reach, 13/16 in hex head, projected tip, copper core. RJ12YC resistor plug, 14mm, 3/8 in reach, 13/16 in hex head, standard projected core nose, copper core design.