That's why the axle must be positioned at normal ride height BEFORE tightening the bolts on both ends of the links. All the links are made the same way -- a steel sleeve that is clamped in place by the bolt vulcanized with a large rubber bushing to the link itself.
I've seen all steel replacements, but I suspect you would have both changes in handling from a lower spring rate and rear end sag if you used them.
Peter
