So I have this 30th anniversary z28 that I brought blind a few months ago. Due to certain laws where I am, I was unable to register it until mid january, so It is still sitting in the garage unusable.

I start it up regularly but I am noticing this strange noise. I might just be being paranoid, but what do you think? It also seems to backfire a bit if i rev it up

heres a vid i made:

1997 Chevrolet camaro LT1 engine rattle - YouTube

 

Sorry Grasshopper couldn't tell much by your video. To start I would check all your accessory pulleis and the belt tensioner. Is your belt in good shape, no stands hanging off of it slaping things as it goes around.

 

I've had that sound in more than one car in the past. Sounds like your A/C pulley/clutch may be shot.
Remove your belt and check your pulleys for noise, slop, and/or a rough feel when spinning. Start with the A/C.
If your A/C still works, turn it on. See if the sound goes away when the clutch engages. If it does, you know right off what it is without having to remove the belt.