If your 1979 F350 4WD has a 460 w/a 4 speed, both were swapped in.
460: 1973/79 F100/350 2WD's only.

Could the frnt end been swapped in? May B the tag's off. No 1 can tell what's transpired over the years unless runnin all the prt #s. I think that's why so many try to get em "back to stock" (all mixed up prts. I'm only 1 guy but I say: "So what"). I forget the initial question, it's gone over a new page & is not available to me here...importance is : Whadda you have for an end goal? Wanna have a pristeen truck w/ a purple frame U can jack up to show your buddies? Wanna go wheeling? Wanna make some money haulin, towin, plowin? All's good 2 me.