I found those when I rebuilt my 85 engine. Of course I put a new timing set in w/ steel guides because I was rebuilding it, but if I was in your situation I would put a new timing kit in with metal guides. I got mine from LCengineering, and I think ENGNBLDR sells them too. Mine broke bad enough that the timing chain got enough slack to jump teeth and cause issues. The pieces also got sucked onto my oil pickup tube = no oil pressure and since the chain tensioner uses oil pressure to stay pumped up, it let the chain go very slack. Timing chain covers, if you need one, can be had from junkyards. Or try putting a wanted post on here. I can always find one if I need one, they shouldn't be too hard to get a hold of.

Here is mine:






and a chip for size reference: