Been tearing down an engine I thought was a 26 27 checked the serial numbers 12235814 that makes it August 6 1925 if I read right.
The crank has a very large Ford logo none of the rest of my cranks have that.
Now to see if the wide brake drum has only one bushing. Book says that was August 8 1925.
The hogs head has the deflection fin for oiling the transmission.
JUL 27 Engine production records, Ford Archives
Last old style engine (12,218,728) built at 5:51 P.M. and new (1926) type engines began on the third shift.
The hogshead deflection rib was added mid year 1924. Advertising for the improved 1926 model started at the end of August 1925.
Late August is when the 26 was released for sales and advertising. They had to be built before that.