Why didn't you take both from the same location. The hot clip sounds mostly like exhaust.
It sure sounds like a rod but it should be louder hot. You could try disconnecting a plug wire at a time and run. If it gets quieter that is the bad rod bearing.
I think you should just run this until it blows up. Run some cleaning oils to see if its a lifter. If we really think this is a rod bearing we'll just have you run thicker oil with some Lucas oil stabilizer. It'll probably run years like that. It took a few years for the SBC in my vette to blow up.
It sure sounds like a rod but it should be louder hot. You could try disconnecting a plug wire at a time and run. If it gets quieter that is the bad rod bearing.
I think you should just run this until it blows up. Run some cleaning oils to see if its a lifter. If we really think this is a rod bearing we'll just have you run thicker oil with some Lucas oil stabilizer. It'll probably run years like that. It took a few years for the SBC in my vette to blow up.