Ford called these "Super Duty" engines, a term they started using in the 1960's.

These engines probably would have been in an F 900, depending on the year. Do you need a replacement for an engine? Or are you looking at one of these as repower option?

As was said, there are better engines, specifically the 370 or 429 "Lima" engines (Ohio, not Peru) that came in later trucks.

Good luck.