Champion 18mm SPARK PLUGS for Early H-D Motors

H-D #37-09B, 37-09C, 37-09D, 37-09E
Champion SPARK PLUGS (Pair)
USA made - 18mm Thread
for 1948 & earlier Harley Knuckle & UL motors (1955 & earlier 45 & Servi-Car motors)
Thread reach of these modern Plugs is 1/2"
Original HD Air Cooled Plugs was 3/8"
Available in equivalent Heat Range of OEM Spark Plugs #1, #2, #3, #4 & #5

SET GAP AT .025" - .030"