<VV> Junk in oil cooler

[Joel McGregor]

I'm working on a 37k mile '66.  I took the oil cooler off to clean it and it had some chunks of what looks like hard rubber inside it.  They were roughly 3/16-1/4" square in size but they clearly weren't made that way.  Where could they have come from?  I guess I'm going to have to tear the engine down to get it all out assuming that there is more inside.  The engine sounds tight but the oil pressure light comes on at low idle when hot.
I can't figure out how these could have made it past the oil pickup screen...
Joel McGregor