Another example… 1954 235 full pressure passenger engine with std trans, SN xF54Z, now in a '53 with PG. The head is casting # 3837161. It's a bit of a "mystery" head, and doesn't show up in the databases I've searched. It's not uncommon, either, since there are numerous posts by people trying to ID the head, on various forums. One suggestion was that it may be a Canadian head? IDK.