Imperial Vehicle Designations & Engine Codes

Sources include Chrysler Service Manuals, Motors Service Manuals and Chilton's Service Manuals. Duplicate information is not repeated. EXAMPLE - 54 to 59 pt gap is the same, so its only entered once! " Marks are used to note repeated information in a column, * marks are used to refer to notes after a subject, -- is used where no data was available at this time. 

*Some references denote the 55 and 56 as a C-73 and the Crown as the C-70. The 1956 Crown models used the same model number as the 1955 as there were few unique changes done to the model. The C70 used the regular production front clip and dash, but on the rear the C70 tacked on a fin instead of being updated with the new rear quarter panels. Thus Chrysler Engineering continued the C70 model designation. Chrysler Engineering added the "*" to a model designation when it was used for more than one engineering mode year (which was not always the same as the marketing department's model year)

• 1957: IM1-1 (base), IM1-2 (Custom), IM1-4 (LeBaron)
• 1958: LY1 -L, -M, -H**
• 1959: MY1 -L,-M,-H**
• 1960: PY1 -L,-M,-H**
• 1961: RY1 -L,-M,-H**
• 1962: SY1 -L,-M, -H**
• 1963: TY1 -L, -M, -H** (with the serial nos. separately 58-63)
• 1964: Crown; VY-1 92-43100001 and LeBaron; VY-1 93-43100001
• 1965: Same as 64, with Crown; AY-2 Y2-53100001 and LeBaron AY-3 Y353100001.
• 1966: 13 digit codes started with the digits as follows: 1st. - Y (Imp); 2nd.- price class L, M, H, P (low -med-high-prem); 3rd. and 4th. - body type: 23 (2dr), 27 (convt), 41 (4 dr.sdn), 42 (4dr.town sdn) and 43 (4dr. hdtp); 5th. -engine size G - 413, J - 440; 6th. - Model Year: 7th . - Assembly Plant, 3 Jefferson, 6 Newark, 8 Export; Last Six Digits - Production Sequence Number when the car was built.
• 1967: Same as 1966 except body type 42 is deleted and engine codes are G=383, J=440 and K= special order.
• 1968: Vehicle numbers are next to the windshield on the left side. The sequence is the same as 1966 except that body type 42 and premium price class are deleted,. G = 383, H= 383 h.p., K=440, L = 440 h.p. M=s.o.
• 1969: Same as 1968.

**Most literature includes the Custom series as -L,. the Crown series as -M and the LeBaron series as -H.

1966-1971: Engine and Model Numbers are included in the serial number on the drivers door pillar, with a prefix for the series and a serial number that followed it.

1954: C542-8-1001

1955-57: Prefix "C", E "engine number", digits 55-56-57 depending on year, and then the numbering starting with 1001.

EXAMPLE : CE561010 - 1956 Imperial, engine number 1010.

1958: the digits "58" followed by "C" for Imperial then the number sequence 1001 etc.

The prefix was followed by month/day the engine was assembled. There may also be special codes stamped for variations in cylinder bores, crankshaft journals, compression, performance or special use.
The "R" in the 1959 number stood for "Raised". This was more important for the 383 as the American Chrysler Windsor and Saratoga used the RB block 383 while all the other car lines used the (low) B block. Thus in 1959 you would find engine numbers ML38- and MR38-. 64-67: Stamped on a boss behind the water pump and next to the distributor with the following numerals:

During the 1968 model year Chrysler began stamping the VIN on the engine, right side, just behind the engine mount and just above the oil pan. Although some of the early models had the full VIN, it is usually just the last eight digits of the VIN.

When the number was moved to the left rear of the block, Chrysler began using a longer, more detailed engine number :
[Engine Plant] - [Engine Size] - [Special Codes] - [Assembly Date Code] - [Daily Sequence Number]