The only diesel option ive ever heard of in a c series truck was the cat 3208 "ford v636" engine.. A 6v92TA engine would be awesome in one of those trucks.. Dont think Ford ever put em in but Im sure they're out there.

Ive been thinking of repowering a c900 crane Ive been holding on to. But dont want to use a 3208 because of personal experiences with the engine.. 6v92 would be a good candidate though.. Big cam 400 would be reall