Indeed, long lived engines are not unusual
Chrysler LA - 1964-2003
Ford Windsor 1961-2000
Ford Inline 6 1960-2016
Modular V8 1990-2014
The BMC A Series is another exceptionally long lived one. 1951-2000 in original form, and then licenced by Nissan until 2009.
> Modular V8 1990-2014
Still lives to this day. The 5.0/5.2 engines are modular.
Nissan VQ series, 1994-today
The BMC A Series is another exceptionally long lived one. 1951-2000 in original form, and then licenced by Nissan until 2009.