Picked up a 2001 C5Z with some mods, cam, kooks, short shifter, coil overs remote bleeder. That has 80k, got it at 75, and it has started to make a strange noise that I can only describe as baseball card in a bicycle wheel. 

It sometimes goes away if you let off the gas or with the clutch pedal depressed but not always. There is no vibration with the sound, if you were deaf you would have no cue, the car drives all the same.   

The clutch has always felt great, consistent bite, never felt it slip. And the car already had a remote bleeder installed so I changed and bled  the clutch fluid(it was black)but that didn’t see to have an effect. It has made this noise before but it seemingly comes and goes. And having the car on the lift I can tell someone has had that metal cover over the torque tube off given how many witness marks there are on the fasteners. 

I have almost convinced myself it is the torque tube, but I am pretty new to corvettes so before I tear into learning this job, is there anything else I can check? Could the shift linkage cause a sound like this? Maybe something in the FEAD? 

I tried to attach a video with the sound it is making. 

Strange noise