[patrickt]

You know your original post sounded like you weren't 100% sure whether you had a hydraulic or mechanical cam in your engine. My audio link in my signature has the hi-def microphone right over the engine at the tail end of the idling audio snippet. You can hear the "sewing machine" sound of my solid flat tappet and it will give a little insight in to how they normally sound. If you pull your valve covers and there is no lash on any of your rockers then it's probably not a mechanical cam.