How to read a Ford service part number

The three parts

The prefix

The prefix has four characters.

1. The first character is the year the design was released. In the system Ford has used since 2010, A is 2010, B 2011, C 2012, and so on; I, O and Q are skipped. So BC3Z was designed in 2011 and HC3Z in 2017.
2. The second and third characters are the vehicle line it was designed for.
3. The fourth character is the source. Z marks a Ford service part: the number you order with. A number stamped or cast on the part itself is often an engineering number, with a different letter in this position (E for engine, for example). If the only number you have is one read off the part, send it as it is and say where it came from; the part is identified before quoting.

The year in the prefix is when the design was released, not when it fitted. A part designed in 2017 can be fitted to trucks built in 2019 and later. That is the main reason year ranges built from part numbers overlap.

The base number

The base number identifies the kind of part, and it is the most useful thing to search by. These are the base numbers on the SGS Engine Parts Ford 6.7L Power Stroke list, all on the reference index:

The suffix

The suffix distinguishes versions of the same part. A revised design gets a new suffix, or a new prefix when the change is larger, and the earlier number is often superseded by the later one. Two numbers with the same base number and different prefixes or suffixes are therefore not automatically interchangeable, and not automatically different either: the supersession record is what settles it.

Why one part has several numbers

Ford numbers a part when it is designed, and numbers it again when the design changes. A truck built during a changeover can carry either version, depending on when it was built, and a later number can replace an earlier one for every year that one covered. The result is that ranges overlap by design, and a year table cannot say which number a particular truck needs. The engineers who answered our own questions put it plainly: every manufacturer does this on purpose.

That is why SGS Engine Parts starts every enquiry from the number, not the year. Send the number you have, and the part and its contents are confirmed before quoting.