Crickets or chirping sound upon light acceleration, only when in motion?

Hello,

I have the car listed above Z51. I recently swapped in some new headers and noticed a "crickets" sort of noise when gently accelerating. Once past 2,000 RPMs or so the noise disappears. I've already smoke tested the entire intake and exhaust systems and have not found any leaks around the usual suspect points (mating surfaces/gaskets, including gaskets between the headers and cylinder head, and headers to catalytic converters). What's even more strange to me is that the car needs to be physically moving and in gear for the noise to be present. Getting a good recording or narrowing down where the noise is coming from is incredibly challenging. No CELs or any indication that the engine is running poorly, just a dastardly difficult-to-troubleshoot noise issue. Any tips? The timing of it all bugs me as this noise was absolutely not present before the headers were installed.

Edit: I don't think it's related to belts pulleys but can't entirely rule it out. They're located on the front (back?) Of the engine closest to the front of the car, and quite a distance from any work that was done installing the headers. With only 2,800 miles on the car at this point, I would hope all is in order from that perspective.