I just finished changing the oil to ROTELLA and with a warm engine and new oil the noise is still there. Using my new stethoscope it appears the sound is coming from #3 and #5 exhaust valves or at least that is the loudest area. Also I ran the RPM up to 3000 and held it for a couple of seconds and I did notice a small miss that I hadn't noticed before. Maybe this additional information will help. I had a long week so I will not do compression test until tomorrow because if I start now I won't stop until finished. Any other suggestions?