Bunp!
Old insert compared to whatever that part number I have earlier was:
Flange comparisons, which I don't think matter.
I think they're 1/2" hole, so they fit my '90 front spring perfectly. If the later trucks have larger spring eye bolts you could possibly still them out and get another steel sleeve.
Couple of measurement pics. OD/ID of the steel sleeve:
OD of the Poly, I can get an ID as well if it matters.