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theCamaro.com Engine Code Decoder:
Chevrolet Engine Code Identification and Decoding
Identifying the engine that is in your vehicle can not only be important to you as in some cases it can help to provide proof of a cars options but if it is not your original engine it would be very important to the person that owns the car it came from. During our years of research we have found original small and big block engines including COPO engines in a wide variety of places including passenger cars, trucks and even boats to name a few.
So where to begin? Start by looking for the engine assembly stamp located directly in front of the passenger side head on a small pad located just above the water pump as seen in figure 1. It may be covered by paint so if you cannot read it try removing the paint with a mild paint remover. DO NOT USE ANYTHING ABBRASIVE. The reason for not using anything abrasive is that if the original stamp is there then the original machine marks from when the block was made may be present. These go a long way to help authenticate the possible originality of an engine stamp.
So you found a code, great, the next step is to find out what it belonged to originally. If it came in your car and was a high performance vehicle like an SS350 or Z28 then just to the right of the assembly stamp will be a partial VIN number in vehicles made prior to 1969 figure 3. This number will be the same that appears on your title and VIN tags if it is original to your vehicle. On certain 1969 and later model cars this VIN number will be missing, do not worry it is likely in another location, on the pad directly above your oil filter next to the transmission bell housing figure 2. If the partial VIN is yours simply look for the last two digits of the assembly stamp. For example a 1967 Camaro with the assembly stamp of T0525MQ would be searched for by looking up MQ under the Camaro section and it would return as an L78 375hp 396 engine. For late 1969 and later vehicles this last section of the assembly stamp may consist of 3 characters instead of two so the code may read something like T0614CKO. In this case the last 3 characters will indicate the engine type instead of the last two.
So what does the rest of the stamping mean? Well the stamp consists of several parts. The first is the assembly plant where you engine was created an assembly stamp starting with the letter T for example would be for the Tonawanda assembly plant. The next two digits are the number for the month that it was assembled as an example 05 would be May. The next two numbers in the stamp will be your engines assembly day as an example 25 would be the 25th day of the month. So T0525MQ would decode as Tonawanda, May 25th, 396cid rated at 375hp.
|1965||F= Flint, Michigan|
|1965||T= Tonawanda, New York|
|1966||F= Flint, Michigan|
|1966||T= Tonawanda, New York|
|1967||F= Flint, Michigan|
|1967||K= McKinnon Industries|
|1967||T= Tonawanda, New York|
|1967||V= Flint, Michigan|
|1968/9||F= Flint, Michigan|
|1968/9||K= McKinnon Industries|
|1968/9||S= Saginaw Service|
|1968/9||T= Tonawanda, New York|
|1968/9||V= Flint, Michigan|
|Assembly Month||01= January|
|Assembly Day||The assembly day is the day of the month that the engine was produced.|
|Engine Suffix Code||The engine suffix code is a two or three digit identifier used during assembly to indicate an engines usage and horsepower rating. For example in 1969 an engine ending with the code MO would have been used in a Camaro where the 425hp 427cid COPO 9561 engine option was ordered.|
|Partial VIN||Partial VIN starting with the year of the vehicle that the engine was originally installed in. This code should be an exact match for the two hidden VIN numbers located on the vehicle as well as matching the last 8 digits of the VIN plate attached to your vehicle.|