Matching Numbers 1953-1967
A Guide to 53-67 Corvettes
BY: Bob Kroupa of Vette-N-Vestments
Frequently, you will read or hear someone talk about a Corvette with "matching numbers". For the uninitiated, it lends a bit of mystery to the Corvette mystique. In reality, "matching numbers" commonly refers to the original Corvette motor that was installed when the Corvette was built. A "matching numbers" Corvette can be valued at thousands of dollars more than a Corvette without the matching numbers.
Since identifying the procedure to see if a Corvette has matching numbers is a lengthy process to explain, we are going to concentrate on Corvettes in the 1953-1967 model years. An article covering the 1968 and later models will follow soon.
As one might expect, many of the original motors in vintage Corvettes have been replaced for a variety of reasons. Replacement motors are readily available and can be the correct motor for the Corvette. However, a Corvette with a replacement motor is NOT a matching numbers Corvette.
In order to determine if the Corvette has a matching numbers motor, we need to start with the serial number or VIN (Vehicle Identification Number) of the Corvette. The VIN on the 1953-1967 models identifies the specific model, the year built, the assembly plant and the production number of the Corvette. As an example, the 50th Corvette built in 1953 would have a VIN of E53F001050. The "E" relates to the model (Corvette), "53" is the year built, "F" is the assembly plant (Flint, Michigan). The production numbers started with 001001, thus 001050 was the 50th model Corvette built.
The VIN on the 1953-1955 can be found at the top of the left hand door pillar just below the courtesy lamp door switch. On the 1956 through the early 1960 models the VIN is on the door hinge pillar just below the upper hinge. It can be found on the steering column under the hood on the early 1960-1962 models. In the mid-years, 1963-1967, it was moved to a location below the glove compartment.
On the mid year models, the VIN also identified the body style of the Corvette. An example of a 1963 Corvette with the serial number of 30837S121449 relates to a 1963 Coupe built late in the model year. The breakdown of the serial number is "3" (for the year 1963), "08" identifies the model (Corvette), "37" represents a Coupe (67 denotes a Roadster), "S" represents the assembly plant - St. Louis, and the remaining digits identify the build sequence. Again, the build numbers for 1963 started with 100001 and ended with 121513.
The final step in determining a matching numbers Corvette is the motor number. In 1953-1955, the 6-cylinder 235 had an engine number stamped on the right side of the block to the rear of the distributor. An example of this number could have been LAY507604. To decode this number, the "L" means 1953; "AY" designates the engine build plant (Tonawanda), the type and transmission (235-Powerglide); and "507604" indicates the engine serial number. Unfortunately, on these models, there is no correlation between the VIN and the motor number. This makes it difficult to determine if this was the original motor that was installed when the Corvette was built.
During the 1955 model year, the first V-8 was introduced for the Corvette, this was the 265 motor. It also had an engine identification number. An example could have been 04080422F55GR. Broken down, the first eight digits (04080422) relates to the motor build number, the "F" identifies the plant assembly location (Flint, Michigan), the "55" denotes the year, and the "GR" identifies the engine type and transmission (265 V-8 with a 3- speed manual transmission). A "YG" designation would be for a 235 6-cylindar with Powerglide, and an "FG" would denote a basic 265 with Powerglide. The engine number appears at the front of the engine block behind the water pump.
Again, original motors are difficult to determine since there was no correlation between the VIN and motor number, itself. However, a change was made in the motor identification for 1957. The change eliminated the sequence build number and added the month and day the motor was built. A typical number would have been F228EM. In this case, the "F" relates to the assembly plant (Flint, Michigan), "2" relates to the month of February, "28" refers to the day of the month, and "EM" identifies the type and transmission (283-250 Fuel Injected with manual transmission).
Incidentally, there were eight identification codes for the 1957 engines. And that number grows with the later models in the late fifties and the mid years (1963-1967). For help in decoding these numbers, your best bet is to view the related publications available in the VetteFinders.com Bookstorewhere you will find publications that provide a complete breakdown of the engine codes and more.
The change in engine identification brought us closer to determining if the Corvette had the correct motor, however, the dates were not the same as the VIN of the Corvette. The "date only" identification continued through the 1960 model year.
The engine number can be found on a pad on the front right side of the engine block just below the bottom of the valve cover. For purposes of this article, the location continued through the 1967 model year.
In the 1961 model year, an important series of digits were added to the engine code. In addition to the manufacturing location, month and day of the build, and motor identification and transmission, the all important six digit sequence build number of the Corvette was added to the engine identification. Again, it was the last six digits of the VIN. An example is a 1961 Corvette with a VIN and engine number as follows:
· VIN 10867S100848: "1" is the model year of
shows the model (Corvette), "67" shows the model (two door
"S" identifies the assembly plant (St. Louis), and the last
indicate the production number.
· Engine number F0228CQ100848: "F" identifies the manufacturing plant as Flint, Michigan, "02" is the build month of February, "28" is the day of the month build date, "CQ" is the base 283-230 motor with a manual transmission, and the all important matching number from the VIN of 100848.
This basic explanation should prepare you to identify that special "matching numbers" Corvette.
When asking about a matching numbers Corvette, be prepared for responses that indicate one or more of the following, "I'm not sure", "I don't know", "I never checked", "I was told it was the correct 327 motor". Often these responses are an indication that the numbers do not match. You will have to check the numbers to be sure if they are correct. Bring a cloth to clean the numbers pad which is often covered by grease and grime. Also bring a small powerful flashlight to read the numbers in tight spots.
A common problem you may encounter when looking for the numbers on the engine pad is that you will find nothing. This is an indication that some motor work has been done and the pad was "decked", thus removing all of the numbers. Another problem that has surfaced in recent years is finding an engine that has been re-stamped to reflect matching numbers. These may appear on "big blocks" (fuel injected, 396s, 427s) that command the high prices. When in doubt, hire an expert to assist in the evaluation of a Corvette.
Now it is time for you to check the numbers. Hopefully, you will be looking at numbers that indicate you have found yourself a "matching numbers" Corvette!
For more information about other C3 technical projects, check out these publications available at the VetteFinders.com Online Store:
Catalog of Corvette ID Numbers
Uncover the mystery of decoding body plates, VIN tags, engine numbers, transmission codes and axle codes
Corvette Restoration & Technical Guide - Vol. 1
Covers 1953-1962 Corvettes
Authentic Restoration Guide
Information packed reference guide for Mid year Corvettes
Corvette Restoration Guide
No Corvette library is complete without the ultimate Corvette reference guide
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