Grandfather's 68 SS Camaro.

[COPO]

Agree with the others, for a permanent fix, you're talking about pulling the engine, disassembly, inspection, and likely a rebuild. The missing metal had to go somewhere and that means the oil, into the bearings, etc. No quick fix here unless you want something short term, but think you're in for a rebuild, or pull the engine, set it aside and drop in a running unit until time / funds allow a proper rebuild if that engine is something worth saving.

Also, probably smart to disconnect the battery before proceeding further.