1937 - 1948 Harley-Davidson Big Twin Sidevalve Flatheads
UL 74" FLATHEADS Made 1937 - 1948
ULH 80" FLATHEADS Made 1937 - 1941
1937 Models - First Year Production:
Note on this early 1937 UL motor the '30 - '36 type VIN
Numbers/Letters-
Later 37 UL changed to Letters & Numbers used thru to later '40s
1939 Model:
1940 Models:
1940 UA Military Model:
1941 Models:
1941 Combination:
Rare 1942 Civilian Model:
Rare 1944 Civilian Model with update chrome:
Rare 1945 Civilian Models: