Subaru engines are identified by MODEL, SPECIFICATION, and CODE NUMBER.
For each model there may be many different versions called specifications. Each
specification will be unique in some way. The difference may only be the paint color
or it may have a different type of PTO or some other significant
In order the identify the correct service part number, it is important to confirm the
specification and code numbers for your engine. The specification and code number
together are known as the PRODUCT NUMBER.
All Subaru 4 cycle engines have a Product Number label similar to the labels
The Product Number Label has a 15 digit alphanumeric string that consists of
the SPECIFICATION (SPEC) number (11 digits) and the CODE number (4 digits).
Please note the illustration below: