do this sound like a spun bearing?
i took the valve covers off and everything was tight and seemed to be ok so i guess its not in the top end

after i drive it for a little bit it goes away though, i dont understand that.
Even on LS1's you can disable injectors one at a time, it will have them same effect.
For the wire test ;
I usually take a pair of bent needle nose pliers, & hook a jumper wire to them & ground.
With gloves on pull one at a time while idling, see if noise changes.
Then you'll know for sure it's bottom end.
In other words looking closely at the oil & depending upon the severity of the problem the oil will have small metal particles in it.



