Very durable engine, long service life, some known mods, hot rods were made by swapping the similar but not interchangeable Chrysler-DeSoto-Dodge truck 237, 251, 265" flathead (known as the 25" engines, the Ply-Do was the 23" engine).
Replaced by the slant in 1960.
http://victorylibrary.com/mopar/m-table-c.htm#Chrysler
