92CamaroRS

Hey Everyone. I jus recently bought a 2000 Camaro z28 was a wreck or so I thought but did the fender rail and so forth. To make a long story short have a pretty bad knock cant really tell where its coming from have a feeling it could be a piston pin but, it goes away at a higher rpm around like 2200 or so. Anything you guys can recommend on checking out. I tried changing the oil, running the car for awhile ( cause it sat for god knows how long ), put fresh gas in it, also disconnecting the spark plug wires while running to see if it got worse or not. Any feedback would be appreciated. Thank you.