What year did Henry change from the low head to the high head?
1917?
The date of change in the drawing is 05-17-17, but all old stock was to be used up first, so 1918 model year cars starting from august 1917 would probably all have high heads?
http://www.mtfca.com/encyclo/E.htm#eng3
As Roger said above, the high heads probably did not appear until sometime in the 1918 model year (August 1917 or later).
All three cars below have low heads.
My unrestored '17 roadster with a May 1917 motor number. Known history since new.
The Rip Van Winkle touring - June 1917 motor number.
My father's late model year 1917 touring - July 1917 motor number. The car has a known history from new and was purchased from the original family in 1949 in very good, unrestored condition.
All three cars above were originally owned by Minnesota residents and they most likely were assembled at the plant in downtown Minneapolis. The original owners lived in the following locations:
My car: Cokato, MN (50 miles west of Minneapolis)
Rip Van Winkle: Chisago, City, MN (50 miles northeast of Minneapolis)
My dad's car: Buffalo, MN (35 miles west of Minneapolis)
My dad bought my '17 from the original owner 62 years ago. It was built in mid June 1917. It has a low head that is original to the car.
Eric's dad took these pictures that day:
Sorry I meant Erik!!!!!