BIGWOODY said:
if you run leaves in the front, it may work fine with any year, I don't really know.
78-79 are ideal, anything else should be a compromise on cost. These are 69.5in WMS and 31.5in center to center perch width, king pin, usually 4.10 gears, 1330 Drive shaft yoke, usually come with small 1/2in wheel studs, are 35 spline inners but not 35 spline outers (needs to be upgraded) the inner shafts neck down abit.
The 1980+ F350 fronts have wider perch seperation (Leafs will be mounted out side of your frame rails...
With 42in tires on centered 8in wide rims My 42s bairly clear my frame and leafs on a 78-79 leaf sprung front. To use a 1980 + you would have to run mush less BS making it WAY too wide, or you could narrow the long side 3in and get less BS rims, or you would have to make links and attach them to the casting on the Drivers side of the axle but they the links could be too close to the front drive shaft....like BIGWOODY said.
Narrowing the front afew inches is not really too bad, the rims with less BS will give you better Hub protection, My front hubs are really getting beatup by rocks, Eventually Ill need to replace them with Flanges $$$.
I havent broken any shafts yet, but the new 4:1 and auto might fix that.