Harley models by letter designation, correlated to year and type

Model Years Description
D........... 1929 - 1931 45" SV
DL ........1929 - 1931 High Compression 45" SV
DLD..... 1929 - 1931 High Speed 45" SV
E ...........1936 - 1950 Medium Compression 61" OHV
EL .........1936 - 1952 High Compression 61" OHV
F ...........1941 - 1950 Medium Compression 74" OHV
FL......... 1941 - 1965 High Compression 74" OHV
FLE ......1955 - 1965 Special cam police 74" OHV
FLH..... 1955 - 1965 High Compression Sport 74" OHV
G ...........1937 - 1963 Servi-Car with tow bar
GA ........1937 - 1963 Servi-Car without tow bar
GD ........1937 - 1941 Large body Servi-Car without tow bar
GDT...... 1937 - 1941 Large body Servi-Car with tow bar
R ...........1932 - 1936 Low Compression 45" SV
RS......... 1932 - 1936 45" SV with Side Car
RL......... 1932 - 1936 High Compression 45" SV
RLD ......1932 - 1934 High Speed 45" SV
RLDR.... 1935 - 1936 High Speed Race 45" SV
U............ 1937 - 1948 Medium Compression 74" SV
UA......... 1939 - 1940 Low Compression US Army 74" SV
UH .........1937 - 1941 Medium Compression 80" SV
UL .........1937 - 1948 High Compression 74" SV
ULH...... 1937 - 1941 High Compression 80" SV
V ............1930 - 1936 Standard Compression 74" SV
VHS....... 1934 - 1936 Medium Compression 80" SV
VL.......... 1930 - 1936 High Compression 74" SV
VLD....... 1930 - 1936 High Compression 74" SV
VLH .......1934 - 1936 High Compression 80" SV
W ............1937 - 1952 Low Compression 45" SV
WL.......... 1937 - 1952 High Compression 45" SV
WLA....... 1940 - 1945 and 1949 - 1952 US Army Low Compression 45" SV
WLC .......1942 - 1943 Canadian Army Low Compression 45" SV
WLD........ 1937 - 1942 High Speed 45" SV
Via: http://fucdatbirth.blogspot.com/2010/09/useful-harley-model-chart.html