Re: 1957 Johnson 10hp and 18hp gears Home › Forum › Ask A Member › 1957 Johnson 10hp and 18hp gears › Re: 1957 Johnson 10hp and 18hp gears MumblesReplies: 5764Topics: 298 July 2, 2018 at 7:23 pm #78908 They must be if both motors use the same 377147 gear set. I checked my ’57 FD parts manual and it only gives a P/N for the complete set, not individual gears.