Ok this sounds vague, I was tearing down the lb9 from my 1987 Camaro. I had the motor on a engine stand oil pan facing up. I took off the oil filter then used a large socket to remove the threaded hollow plug that the filter screws onto. When I pulled up the oil cooler a snap ring fell onto the block. The ring is about 3/4" or so in diameter. It didn't look like it fell off of anything. I don't know where it came from and it might be important when I put things back together.

I will get a picture in the morning. Just wanted to get this ball rolling.