Hey Gents...
I had this same thing. Had the rig in for service - same deal. "Normal condition." BS. The sound sounded much like the exhaust was choked. Then combine a slight "tick". I had a feeling it might be the valvetrain. sooo...
Here's a suggestion before you go tightening. Seem to work for me. With my older Porsches, the engines would get gunked up in time. Just before every oil change, I would run a bottle of "Techron" through the system. The stuff works really well to clean out all the crap and build up.
Following that I would change the oil with Mobil 1 5W30. So far, the engine is MUCH quieter. So much so the wifey actually noticed it too. Engine now has the usual V8 rumble.
Food for thought.