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Decoding Engine Block Stamping #'s
1960-1964
From '60 to '64 a typical engine ID code will look like this: S42-222
The first digit identifies the year: S=1962
The next 2 digits are the first 2 digits of the engine CID: 42=426
The last 3 digits are the date and month: 222= February 22
1965 - 1971
In '65 the third digit of the CID was added to the engine ID code.
After '65 a typical engine ID code will look like this: B383-322
The first digit identifies the year: B=1966
The next 3 digits are the engine CID: 383=383
The last 3 digits are the date and month: 322= March 22
Year Codes for B & RB Engines
A - 1965
B - 1966
C - 1967
D - 1968
E - 1969
F - 1970
G - 1971
H - 1972
J - 1973
P - 1960
R - 1961
S - 1962
T - 1963
V - 1964
4T - 1974
5T - 1975
6T - 1976
7T - 1977
8T - 1978
Other Stampings
Additional stampings may be found on the ID pad. They identify non standard engine components.
A - .020 oversize cylinder bores
Diamond - oversize tappets
E - Cast Crankshaft
HP - High Performance
L or LC - low compression
M - .001 undersize main bearing journals
Maltese Cross - .001" undersized bearing shells
Maltese Cross and an X - .010" undersized crankshaft
O.S. - .005 oversize valve stems
P - premium fuel
R - regular fuel
RX or MX - all main or rod journals .010" undersized
S - special engine
WT or TW - water test
X - .010" undersize crankshaft
'68 and later B&RB engine serial numbers
Beginning in 1968 all Mopar B&RB engine blocks have an engine serial number stamped in the left side oil pan rail at the rear corner under the starter opening.
Sample Serial # PT44028650001
Plant Code: PT
MV,MN - Marysville Plant (426 Hemi)
PT - Trenton Plant (361, 383, 400, 413, 426, 440)
Cubic Inch Displacement: 440
Should need no further explanation
Date Code: 2865. Based on 10,000 day Julian Calendar. 10 000 day calendar. Saturday July 29th, 1961 is Day One
2865 is June 1, 1969
Serial Number: 0001
A sequential number for each days production beginning with 0001
