Deciphering Ford Part Numbers and Date Codes

Ford part numbers are easy to understand once you know the rules. The part numbers are divided into three sections and have the format xxxx-xxxxx-x. Notice the three separate parts divided by two hyphens.

The first part is called the PREFIX. It tells us the decade and year the part was engineered, the car-line the part was designed for and the engineering group. For example let’s use the code C6ZE. the first character is a C this indicated the decade 1960. The second number is a 6 this tells us that the part was designed in year 6 of decade 1960 or put another way, the first two places tell us the part was designed in 1966. The third position Z tells us that the part was designed for a Mustang. The fourth letter is the engineering group the part belongs to. E is engine, if the part is a service part, then the fourth place-holder indicated the division such as Z = Ford division, Y=Lincoln & Mercury, x=Original muscle parts program and M= Ford motorsport SVO.

The second block of letters is the basic part number some codes you might see are:

• 9424 which is small block intake manifold
• 9430 is a right hand exhaust manifold
• 9431 is a left hand exhaust manifold
• 8501 is a water pump.

And the list goes on, and on.

The last section is the revision number. If a part is in revision 1 it is an “A” the second revision is a “B” and so on. Ford does not use the letters i or L since they might be confused with a number one. If the part has been revised so many times that it passes “Z”, they start over with AA, AB,AC, and so forth and so on.

Date Codes

There are three methods to determine the date codes. The CASTING NUMBER tells the engineering level. Then there is the CASTING DATE CODE and finally the MANUFACTURING DATE CODE.

The CASTING NUMBER tells us the date the part was engineered and the engineering/revision level. This code is found on the right rear portion of the block just above the starter.

The CASTING DATE CODE the casting date was the date the part such as an engine block was cast. This code consists of an alpha numeric code such as 6B11. The 6 indicates the part was cast in the year 1966. Looking at the chart below, you can see the letter B represents February, and the 11 tells us that the part was cast on the 11th. So 6B11 is February 11th 1966. This code can be found below the distributor and above the fuel pump on the 260, 289 and 302 engines.

The MANUFACTURING DATE CODE is the exact date the parts was created/assembled. The code is the same as the casting code, but this code is stamped into a flat machined surface on the block such as on a cylinder head. Many times this part is machined off when engine work is performed.

If the model year exceeds the first 12 months then the second year code is used.