Before 1980, the norm for ford crew cabs was to have a short box. From what I could tell they were basically all F350s with D60 front ends if 4wd. Sweet trucks to look at, but unbelievably tough when worked hard.
I've seen an old 1978 crewcab bush truck that was in service till about 2004 before they finally flogged it. That was what they used when the "superduties" were broke down, so it was use almost constantly. D70 rear, D60 front, 4.9L engine and T18 tranny, you can't kill it even if you wanted to.
I did see ONE 1978-ish ford with a crew cab and 8F box, but I think that may have been a back yard custom job (it was nice though).