[get me on the road]

Boog I would suggest, if you think the noise is loud enough, to get the engine warm so it makes the noise your hearing. Then turn the engine off and turn it with a breaker bar to see if you can hear the noise, maybe even pull the plugs and valve covers to see if it makes it easier to locate the sound. With the valve covers off and turning the engine by hand, if you have a good eye you should be able to see if there is anything unusual in the movement of one of the valves. Just something I thought of, let me know if it helps.