New Oil Pump, New noises

I’m working on a 04 Silverado with a 4.8. I was getting very low oil pressure so I replaced the oring. No luck. Replaced the oil pump and now I’m getting great pressure! But now once the engine warms up it’s making a noise from what sounds like is from the timing chain cover. Could it be possible the new pump is bad or not installed correctly? It sounds almost like a train tire on a track if that makes since?

I haven't done an oil pump on an LS, but what you describe sounds like valve train noise, maybe lifter or related. Could have resulted from the low oil pressure you had. If it is good pressure now, I wouldn't think you installed it wrong.