Exhaust pipe attachment bolt (stud) + nut+ w, long, 3/8 inch x approx 6-3/4 inch long for Norton singles 1932 to 1955: on the front for side valves from 1932 to 1938/9; on the rear for military side valves 1937 to 1945 (exhaust pipe rear bolt); on the front for side valves and overhead valves 1946-1955. Measure the hole in your crankcase and frame. The part that goes through tthe frame or engine plates is 3/8inch ; the part protruding from the plates to the exhaust pipe is 7/16 inch. Original part number: 9243; 10245 - exhaust pipe attachment bolt
