It was introduced in 1932, and was used in automobiles until the 1954 model year. In the thirties, gangsters such as Bonnie Parker and Clyde Barrow favored Fords powered by Flatheads, since they tended to be quicker than most cars of the time, they made great getaway vehicles.
It has also known that John Dillinger even wrote Henry Ford, praising his powerful Flathead V8, and thanked him for a designing quick getaway car.
The engine was also popular among moonshiners well into the 40s and early fifties.
The engine was also popular with hotrodders of the era, as well as today's hotrodders.
Because someone would steal them.
What would a flathead do with Calc book?