There are 2 "families" with similar design, with staggered bore pitch and staged main bearing sizes like the 235 & GMC.
Small: "Ply-Do" (Plymouth, Dodge) engines are 218 (a.k.a. 217) with a 23" long cylinder head. Replaced in cars by the Slant 6 in 1960, continued in some trucks.
Large: "Spitfire" (Dodge truck, DeSoto, Chrysler) 237, 251 and 265" with a 25" long cylinder head. The 265 was the Windsor (low price model) engine until the 301" "polyspheric" V8 in 1955.
All very durable.
Some data on my site here: http://victorylibrary.com/mopar/m-table-c.htm#Chrysler

There is an even larger L6 series (413), but only big trucks.