Found on the web and copied. Is this the breakdown you're looking for:
Position #1 is the Year Identification
0 = 1960, 1 = 1961, 2 = 1962, etc. continuing to 9 = 1969
Position #2 is the Assembly Plant Identification
G = Chicago, Illinois
H = Lorain, Ohio
J = Los Angeles, California
Y = Wixom, Michigan
Positions #3 and #4 are the Body Series Code Identification
83 = Thunderbird 2-door
hardtop (1962 through 1966, with rear quarter window)
85 = Thunderbird Convertible (1962 [see note below] through 1966)
87 = Thunderbird 2-door Landau (1962 through 1965)
89 = Thunderbird 2-door Sports Roadster (1962-late [see note below] and 1963)
NOTE: The 1962 Thunderbird Sports Roadster body series code was "85" for the first 558 units produced, the last being 2Y85Z114640. The body series code was changed to "89" for the balance of 1962 production.
Position #5 is the Engine Identification
Z = 390 cubic inch, 4V, V-8 (1961-1968)
Positions #6 through #11 are the Consecutive Unit Number
Consecutive Unit Numbers begin at 100001 at each Ford Motor Company assembly plant. This number represents the scheduled sequence order. When a car was ordered, it was immediately assigned a VIN with a Consecutive Unit Number. It was then assigned a scheduled production date based on availability of trim,
parts, other components, and taking into account downtime and production workloads at the assembly plant.
A scheduled production date was very often out of sequence with the Consecutive Unit Number. And more often than not, the actual production date (the day the car rolled off the line) was earlier or later than what was originally planned. Therefore, a Thunderbird with a Consecutive Unit Number of 105678 may have actually been produced and ready for shipping before a Thunderbird with a Consecutive Unit Number of 105432. The Consecutive Unit Number should be considered to be a unique identification that shows when the order was received and when it was planned for production.
Location of the Data Plate which contains the Vehicle Identification Number:
1960 through 1963 Thunderbirds: On the left front body pillar below the driver's door hinge opening
1964 through 1973 Thunderbirds: On the driver's door lock face.
