It's been done, but is much easier with leaf springs using a pre-80's
F250 dana 44. IMO, there is not much to be gained by swapping one dana 44
for another. The only things you will gain are;
1. Losing one U-joint and the relatively weak slip joint on pass axle.
2. Allow easy 8 lug conversion with solid axle 44.
3. No more wild camber swings with susp travel.
4. Align will hold up better.
5. Somewhat easier dissassembly for maint.
As for flex vs susp, stock bronc's ramp about the same(usually shocks limiting factor) and I've seen both solid axle and TTB ramp 1000 on a 20 degree ramp without going nuts on exotic susp stuff. Most of the flex in the rear susp anyway.
The dana 50 has different length traction beams and uses leaf spring, so it's not a good candidate either. Also uses bastard dana 50 ring gear, although they are using that in front of some new super duty's, so parts may soon be avail for it.
IMO, either swap to a solid axle dana 60 front, or don't bother. BTw, that crossmemeber needed to be modded when one guy swapped ina a dana 60 front for his dana 50 TTB. Dana 44 pumpkin is much smaller and would prob be OK with a mild lift.