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B/RB Mopar Blocks (stock)

Block Serial Number Stampings

(On B engines, 351-400 ci, there is a pad on the right front of the engine below the distributor. On RB engines, 413-440 ci, there is a pad on the left front of the engine. These pads contain stampings that will quickly identify an engine and usually tell you a little about it.)The stampings on the top of the block will look something like this:
 

C H 426 B
8-3-32
(These particular markings are of the form:)
Series / Hemispherical / CID / Bodytype
Month-Day-The Number Engine Built This Day

These marking are noted below. The stamping on the bottom of the block will be the formal serial number for that block and read similar to the following:
9-10-68 PT38326010001. These numbers are decoded as follows:
A. The first numbers are the date of the stamping (9-10-68)
B. The next letters indicate the engine assembly plant- in the case of our example, Trenton.
C. The next three digits indicate cubic inch displacement: 383 cid.
D. The next four digits (2601) are the 10,000 day calender numbers: 2601 = Sept 10, 1968.
E. The final four numbers (0001) show that this was the first engine assembled that day.

SERIES:
S = 1962
T = 1963
V = 1964
A = 1965
B = 1966
C = 1967
D = 1968
E = 1969
F = 1970
G = 1971
H = 1972
J = 1973
4T = 1974
5T = 1975
6T = 1976
7T = 1977
8T = 1978
 

OTHER STAMPINGS:
Diamond = 0.008-in. oversize tappets
Maltese Cross = 0.001-in. undersized crankshaft
Maltese Cross and an X = 0.010 undersized crankshaft
A = 0.020-in. oversized cylinder bore
B = 0.010-in. undersized main and rod bearings
E = cast crankshaft
H = standard 4bbl
HP = high performance
LC = low compression
O.S. = 0.005 oversized valve stems
P = premium fuel recommended
R = regular grade fuel may be used
S = special engine
WT or TW = water test
X = oversized valve guides

ASSEMBLY PLANTS:
K = Toluca
PT = Trenton
M = Mound Road
T = Trenton (400 and 440 only)
MV or MN = Marysville

 

A- B- RB Casting #

2264230 318 1960-66 " A "
2468230 318 1960-66 " A "
2532630 318 1960-66 " A "
2120229 361 1960-66 " B" Industrial
2205712 361 1958-66 " B"
2468130 383 1959-71 " B"
3614230 400 1971-72 " B"
3698630 400 1973-78 " B"
4006530 400 1976-78 " B"
1852029 413 1962 " RB "Max Wedge
2120529 413 1959-65 " RB "
2205697 413 1959-65 " RB " Pass Car
2468030 413 1959-65 " RB "
2536430 440 1966-72 " RB "
3698830 440 1973-78 " RB "