I can't remember but have you checked the cams for any signsof excessive lobe and examinedthe rockers for the same?

If you think you can identify the cylinder making the noise I would move the rockers to another cylinder and see if the noise follows it.

 

There are no signs of excessive wear on cams or rockers. It's stock Gsr cams so it's not like it's a big cam. No unusual wear on rockers either. The noise is loudest on the drivers side on the intake side of the head. The closer to the distributor you go the quieter it gets, at least with my cheap HF stethoscope