Although it's been ages (literally!) since I wheeled in a 1958 f-250, I would hazard a guess that revolving shackles will add travel but there's no weight on the associated tire if the shackle is open. Same as the tire being off the ground.
No weight = no traction. No traction = no go.
I think I would want to see these critters in action before I went to that much trouble and $$$ to do the deed.
Your mileage May vary.
Ray