[sc_rufctr]

I just listened to the video.

That's loud and not good. I'm guessing you could have a stuck or sticky valve. I would bet one of them is binding up in the guide.

Were the valves and guides replaced during the rebuild?

With the valve covers off turn the engine by hand and listen for a thunk as each valve is releases as the cam passes over the rockers.
You may find one that sticks and then thunks as it releases. The good news it's an easy and relatively inexpensive fix.

FWIW... I doubt it's bearing related.