Hey Leif . . .

A different school of thought indeed when it comes to workhorse power plants

low revving big-cube motors!

They apparently got their start in aircraft engines and then moved to boats, trucks and buses:
Hall-Scott History link
Crown Super Coach
Crown Super Coach engine types

Hopefully there is someone out there doing a vintage restore on some big vehicle . . .

[Linked Image from 49fastback.com]