Intermittent Pilot bearing Noise?
 

It's a very short clip and a few years old but you can here the noise just after startup. I've watched a few youtube videos about bad pilot bearings and to me, it sounds very similar. The noise occurs at idle and just above idle. In gear or neutral, with the clutch in or out. I don't believe it is front end related alternator, fan, etc. but rather rear of the engine or front of the transmission. Trans is a T98 for reference. Any thoughts?

In gear, clutch out and you have a noise?

in this situation the pilot bearing will not be turning. Can you confirm?

Intermittent THROWOUT bearing noise.
 

The noise is coming from the throwout bearing, not the pilot bearing.

The throwout bearing (C0TZ-7580-A) is pressed onto a collar (B3TZ-7561-A) that originally had a Zerk (grease) fitting on it.

It's possible that a previous owner replaced the collar with one that didn't have a Zerk fitting.

Or it's present, but hasn't been greased in many years, because some people in "today's world" are unaware of it.

When Ford introduced "Lifetime Lubrication" in 1963, rubber plugs were placed in the Zerk holes, but by the mid 1970's, FoMoCo replacement parts had no provisions for Zerks.

The pilot bearing is bronze, so it was never greased.

I haven't ever seen a zerk on the trucks' release bearing hubs. The release bearings are sealed, I don't know how you could get grease into them. I have heard of the guys with '30's and early '40's cars greasing them, so it could be a late-40's change. No mention of a grease point in the workshop manual. Replacing the release bearing isn't hard but requires trans removal.