Q: Identification Numbers
What are the identification numbers I should look fo to verify a numbers matching Firebird.
A: The question of ‘Numbers Matching’ has always been a topic for debate amongst some die-hard enthusiasts. I thought I’d share with everyone what I’ve discovered. If I’ve stated anything in error, please let me know. Numbers Matching basically means the Body and all of it’s components match according to VIN and Part Numbers, Casting Numbers, Date Codes. The Engine/Trans/Axle are considered the ‘Brain’ of the car and they should be the original parts that came on the car when it rolled off the Final Line. Yes, it is possible to rebuild a matching numbers car but that is a touchy area because it starts to get into ethical and illegal practices. A Numbers Correct Car is not necessarily an original Numbers Matching Car.
– VIN (VEHICLE IDENTIFICATION NUMBER)
Assigned to a Body once it has been scheduled for build (Body in White) prior to Final Assembly (while at Fisher Body). This 13-Digit Number included the Division (Chevy, Pontiac, etc.), Series, Model, Year, Assy Plant, Engine (V-8 or 6cyl). The last 5-Digits were the specific Serial Number. The VIN was stamped into a metal tag riveted to the top LH side of the Dash. New for ’68 was the stamping of the VIN (minus Series & Model) onto the Engine Block and onto the Manual Trans Case. This would have occurred at the Vehicle Assembly Plant just prior to (or during) installation into car. Additionally, there were ‘Hidden-VINs’stamped onto various parts of the Vehicle. Generally, these were stamped onto a part of the frame, upper cowl and sometimes on the rear body section (trunk gutter).
– BODY NUMBER
This was the consecutive body number as assigned by Fisher Body. For 1968, there were 2 Assembly Plants, LOR (for Lordstown, OH) and LOS (for Van Nuys, CA). This number was stamped onto the Firewall Trim Tag and will appear anywhere from a 2-Digit number up to a 5-Digit number. This number will also appear on the Broadcast Sheet. There is no consistent (numerically consecutive) pattern between the VIN and Body No.
– ENGINE UNIT NUMBER
A 6-Digit Number was stamped onto the front RH face of the Engine Block. This was a tracking number used for sequencing an Engine to a specific car. All V-8’s started with a 2 while the 6-Cyl’s began with a 6. This number was most likely stamped at the Engine Assy Plant prior to delivery to the Vehicle Assembly Plant. Also found on the Car Billing History Sheet and on Owner Warranty Data Plate. No consecutive connection to the VIN as this number was not unique to a specific Model.
– IDENTIFICATION NUMBER
Once a car was ordered and scheduled for build, an Identification Number was created and routed through to the Assembly Plant for scheduling. This 6-Digit number was entered into the Broadcast System at Fisher Body and the Final Assembly Plant. This number is found on the Broadcast Sheet and along the bottom of the Window Sticker. There is no direct sequential connection between this number and the VIN although the Identification Number is usually higher than the VIN and does climb higher as VIN does.
– SEQUENCE NUMBER
Found only on the Broadcast Sheet, this number was used within the Plant as assigned by the scheduling dept. Usually a 3-Digit number with no sequential connection at all to the VIN, Body Number or IDENT. Number. Perhaps assigned in batches and/or daily.
– INVOICE NUMBER
A 6-Digit number proceeded by a letter. Used for Billing purposes and found only on the Car Billing History. No connection to any other vehicle number.
– CASTING NUMBERS/PART NUMBERS
Most all parts on a car that were cast usually had a Casting Number. This was usually the part number but not always. Many times it represented an assembly. Engine Block, Heads, Intake/Exhaust Manifolds, Timing Chain Covers, Transmission, Axle Housing all had a Casting Number on them. Additionally, other parts had a Stamped Part Number and/or a Tag/Adhesive Label attached primarily for Operator I.D. during the Assembly Process. Many of the Codes found on the Broadcast Sheets could also have been used on these ‘Tags/Labels’ sometimes still on the part (though, most fell off within a few weeks of delivery).
– DATE CODED PARTS
Along with the Casting Number, many parts had a Date Code Cast or Stamped onto them. Various formats were used to denote the Date the part was cast, and/or assembled. One example is the Engine Block. “L227” represents Dec. 22 1967. Yes, the letter “I” was used in 1968 despite what many magazines/books say. There was also a ‘Julian Date’ code used on some parts. Some Date Codes were built into the Part Number (carburetors). Other items used a unique coding system such as the Transmission, Glass, Alternator and Distributor. Parts that had a Date Code were the Engine, Cylinder Heads, Manifolds, Carb, Alternator, Starter, Transmission, Axle, Glass, Shocks, Gauge Clusters, Tachs, Clocks, Shifters, Fan Blade Assembly, Master Cylinder, Side View Mirrors, Waterpump, Distributors, Mufflers, Brake Drums, Calipers, Steering Gearbox and possibly other pieces. The thing to remember about date codes is the part should be dated before the Body (Trim Tag date). There is no firm rule on how far back the part must be dated before the body. Most agree that parts should be no more than a month or so before the car.
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Content last modified: January 11, 2014 at 8:24 am