It sounds like it is comming from the oil pan, but it dous not sound heavy like a rod.
I would feel the oil pan to see if maybe something is hitting it. Could be a rod nut comming loose and hitting the windage tray or the tray could have come loose.
Does the noise change if you push in the clutch?
What about rockers? Are they Toyota, or are they Napa. I have seen a Napa rocker loose the hardend pad causing a loud valvetrain noise.