We have what we believe to be a 261 engine with a strange Engine Serial number of "FIII4L" (Serial Number found on the ledge by the distributor)
The three "I's" in a row is what I find strange. Could this mean that it is a replacement engine? (non-factory installed engine)

Any insight would be appreciated.

Thank You!
--Tom
Attachments
Engine Serial Number.jpeg (168.58 KB, 78 downloads)