Post up a video. Make sure its ice cold (engine).
Then after it gets to operating temp raise the rpms up to about 2500 and hold.
Drive it a bit and do it again while hot.
If it quiets down?
You have piston slap my friend.
What happens is over time it'll get a little noisier. But it is inherent in the piston skirt design of LS engine.
It's not harmful. Just an annoyance.
If you cut the filter and see nothing in there or the oil? It's either a lifter or piston slap. I'm guessing piston slap as almost every tbss ever made has some.
Some things that cause it to get louder are someone revving it out or beating it up a bit while it's still pretty. Old (oil not warmed up yet - don't go by coolant temps) and it'll beat up the Teflon coating on the skirt.
Watch some videos on YouTube
"LS2 piston slap".
Want to hear a really bad case of it?
Looking forward to your research and investigation.