I've only ever known one to have a problem, was a sunday eve so I fixed it with a rose joint welded to the link arm, with a bolt and washers after welding a bolt in place of the stub.
I'm a bit better these days but would fix in a similar manner if having trouble getting the parts.
Loads of sierra parts on the bay though, my own cossie has done 200,000 miles and no discernable wear that I've noticed so they do last normally.
I'd just raid the scrappies first there's bound to be the same bush on loads of fords, if not, as a last resort one can be made from delrin on a lathe no probs, let me know.
tabetha