I listened again and you guys should too. It's a grinding noise like if a bolt were rubbing on the flywheel or the cam gear. Like I said before, it's a whirring noise. Twice the engine rpm at least. With the cam and slow idle you can damn near hear every cylinder fire. If it was piston slap that would have the same rhythm as the cylinders firing. This noise is double that rhythm.
It's loudest w/ a stethoscope on the valve covers and kinda loud on the shaft.. sounds just like a good ol Cummings! But, I caint hear it with the rocker box off, like you can a clatter/ clickn crap loose valve train
