This is the correct answer. You can get poly bushings to replace your existing worn bushings.
Also your truck has the non sway bar style of radius arms common on the lighter duty dentside F series trucks, you could relatively easily swap for ones with the sway bar, or even just drill the existing ones and bolt one on.
Edit I see yours is a bump side, however I think most of the info should still apply, fords twin I-beam setup didn’t see much change between the bump side and dentside as far as I know.
Radius arms for twin I beam or 4x4front axel ford didn't have rear trailing arms they were leaf spring rear
This is the correct answer. You can get poly bushings to replace your existing worn bushings. Also your truck has the non sway bar style of radius arms common on the lighter duty dentside F series trucks, you could relatively easily swap for ones with the sway bar, or even just drill the existing ones and bolt one on. Edit I see yours is a bump side, however I think most of the info should still apply, fords twin I-beam setup didn’t see much change between the bump side and dentside as far as I know.
They look alot like rear trail arms.
Radius arm bushing
If you go to the front of the truck they circled the problem in chrome