Just thinking out loud. As I was reading this thread I was thinking throughout that you should replace the lifters on that side(at least) & break the cam in again as my thinking has been influenced by several recent threads which ended up being bad lifters as the culprit but after listening to the audio it sounds different from clicking lifters I have heard in the past & sounds like rocker shaft/rocker arm contact. Keep us posted. Inquiring minds(will) want to know.