Early Hemi and related Poly Engine ID codes.

These numbers are stamped on the top front of the block, on the machined surface, just ahead of the valley cover. Although this list seems extensive, it is not guaranteed to be complete, nor is it warranted to be free from errors.
If you can document corrections or additions please send a note.

Chrysler Hemi________________________________

C51 ....... 1951 ...... 331 ....... 2-bbl
C52 ....... 1952 ...... 331 ....... 2-bbl
C53 ....... 1953 ...... 331 ....... 2-bbl (last year)
C54 ....... 1954 ...... 331........ 4-bbl (on all following years)
CE55 ...... 1955 ...... 331 ....... Imperial
NE55 ...... 1955 ...... 331 ....... New Yorker
3NE55 ..... 1955 ...... 331 ....... Chrysler 300 dual 4-bbl
CE56 ...... 1956 ...... 354 ....... Imperial
NE56 ...... 1956 ...... 354 ....... New Yorker
3NE56 ..... 1956 ...... 354 ....... Chrysler 300 dual 4-bbl
CE57 ...... 1957 ...... 392 ....... Imperial
NE57 ...... 1957 ...... 392 ....... New Yorker
3NE57 ..... 1957 ...... 392 ....... Chrysler 300 dual 4-bbl
58C ....... 1958 ...... 392 ....... Imperial
58N ....... 1958 ...... 392 ....... New Yorker
58N3....... 1958 ...... 392 ....... Chrysler 300 factory fitted with
                                    fuel injection, later replaced
                                    with dual 4-bbl by dealers.

Chrysler Spitfire_____________________________________

WE55 ...... 1955 ...... 301 ..... Windsor ....... 2-bbl
WE56 ...... 1956 ...... 331 ..... Windsor ....... 2-bbl
WE57 ...... 1957 ...... 354 ..... Windsor ....... 2-bbl
LE57 ...... 1957 ...... 354 ..... Saratoga ...... 4-bbl
58W ....... 1958 ...... 354 ..... Windsor ....... 2-bbl
58S ....... 1958 ...... 354 ..... Saratoga ...... 4-bbl

Dodge Hemi__________________________________________

D44 ..... 1953 ...... 241 ...... Red-Ram ....... 2-bbl
D48 ..... 1953 ...... 241 ...... Red-Ram ....... 2-bbl
D50 ..... 1953 ...... 241 ...... Red-Ram ....... 2-bbl
D55 ..... 1955 ...... 270 ...... Red-Ram ....... 2-bbl
D55 ..... 1955 ...... 270 ...... Super Red-Ram....... 4-bbl
D56 ..... 1955 ...... 270 ...... Super Red-Ram....... 4-bbl
D500 .... 1956 ...... 315 ...... 4-bbl
D500 .... 1956 ...... 315 ...... Power-Pack....... dual 4-bbl
KD500 ... 1957 ...... 325 ...... 4-bbl
KD500 ... 1957 ...... 325 ...... Power-Pack....... dual 4-bbl
D501 .....1957....... 354 ...... Chrysler engine....... dual 4-bbl

Dodge 'Poly'___________________________________________

D55 ....... 1955 ....... 270 ...... 2-bbl
D63-1 ..... 1956 ....... 270 ...... 2-bbl
D63-2 ..... 1956 ....... 315 ...... 2-bbl
D63-3 ......1956 ....... 315 ...... 4-bbl
KDS  ...... 1957 ....... 325 ...... 2-bbl
L325 ...... 1958 ....... 325 ...... 4-bbl
LD2 ....... 1958 ....... 325 ...... 4-bbl

DeSoto Hemi_________________________________________

S17 ...... 1952.......276...... Firedome....... 2-bbl
S16 ...... 1953...... 276...... Firedome....... 2-bbl
('16' and '17' are not reversed...)
S18 ...... not recorded
S19 ...... 1954 ..... 276 ..... Firedome ...... 2-bbl
S20 ...... not recorded
S21 ...... 1955 ..... 291 ..... Fireflite ..... 4-bbl
S22 ...... 1955 ..... 291 ..... Firedome ...... 2-bbl
S23 ...... 1956 ..... 330 ..... Firedome ...... 2-bbl
S24 ...... 1956 ..... 330 ..... Fireflite ..... 4-bbl
S24A ..... 1956 ..... 341 ..... Adventurer .... dual 4-bbl
S25 ...... 1957 ..... 341 ..... Firedome ...... 2-bbl
S26 ...... 1957 ..... 341 ..... Fireflite ..... 4-bbl
S26A ..... 1957 ..... 345 ..... Adventurer .... dual 4-bbl
S27 ...... 1957 ..... 325 ..... Dodge Engine .. 4-bbl

Plymouth 'Poly'_______________________________________

P27 ....... 1955 ...... 241 ....... 2-bbl
P27 ....... 1955 ...... 260 ....... 2-bbl
-----P27 used for two engines------
P29 ....... 1956 ...... 270 ....... 2-bbl

Note on truck engines; on Chrysler blocks, look for a 'W' cast in
relief between the core plugs. This indicates a 354 block although
the finished bore may be 331. The 'W' is also found on pass car 354
blocks.

Light Duty Trucks____________________________

These can be Hemi or Poly, some numbers were duplicated

VT-334 ....... 1954 ....... 241
VT-334 ....... 1954 ....... 260
VT-336 ....... 1954 ....... 241
VT-338 ....... 1954 ....... 241
VT-338 ....... 1955 ....... 260
VT-338 ....... 1956 ....... 270
VT-350 ....... 1954 ....... 331
VT-434 ....... 1955-1956 .. 260
VT-436 ....... 1955-1956 .. 260
VT-444 ....... 1956 ....... 260
VT-448 ....... 1956 ....... 331
VT-448 ....... 1959 ....... 354
VT-534 ....... 1957 ....... 315
VT-536 ....... 1957 ....... 315
VT-538 ....... 1957 ....... 315
VT-544 ....... 1956 ....... 315
VT-548 ....... 1956 ....... 354
VT-549 ....... 1956 ....... 354
VT-550 ....... 1956 ....... 354
VT-576 ....... 1958 ....... 354

Medium Duty Trucks___________________________________

Hemi, some numbers were duplicated

VT-342 ....... 1955 ....... 270
VT-344 ....... 1955 ....... 270
VT-346 ....... 1956 ....... 270
VT-348 ....... 1956 ....... 270
VTX-442 ...... 1956 ....... 270
C-56 ......... 1953 ....... 331
C-68 ......... 1956 ....... 331
C-72 ......... 1957 ....... 354
C-76 ......... 1954 ....... 331

Heavy Duty Trucks, Busses, (big stuff) ________________

-------some numbers were duplicated--------

B8, C8, D8, F8, FS8, G8, GH8, HS8 .................1955-1956 . 260
J8, JS8, KA8, KS8..................................1955 ...... 270
R8, RS8, T8, V8....................................1955 ...... 331
K8D4, K8D5, K8D6, K8S4, K8S5, K8S6.................1957 ...... 315
K8C5, K8C6, K8C7, K8D7, K8D8, K8P3, K8P4, K8S7,
K8W5, K8T7, K8T8...................................1957 ...... 331
K8C7, K8D7, K8D9, K8T7, K8T8, K8T9.................1957 ...... 354
L8C5, L8C6, L8D3, L8D4, L8D5, L8D6, L8P3, L8P4,
L8S4, L8S5, L8S6, L8W5............................ 1958 ...... 315
L8C7, L8D7, L8D8, L8D9, L8T7, L8T8, L8T9.......... 1958 ...... 354
M8C6, M8D6, M8D8, M8S6 ........................... 1959 ...... 315
M8C7, M8D7, M8D8, M8D9, M8S7, M8T7, M8T8, M8T9.... 1959 ...... 354

Marine ______________________________________

M44S-3 ..................... 270
M45S-3 ..................... 354
M45SP ...................... 331
M45SP-3 .................... 354

Industrial___________________________________________

IND 18, 18A ................ 241  Dodge
IND 19A .................... 276  DeSoto
IND-20, 20A, 24, 24A ....... 331  extended bell type
IND-52 ..................... 260  Dodge
IND-53,54 .................. 315  Dodge
IND-56 ..................... 331  Chrysler
IND-56A .................... 354  Chrysler
IND56A1 .................... 325  Dodge
There are examples of the top of the block not having a stamp 
and the ID may be found on the face of the block, just under 
the head gasket surface on the driver side