Can't Figure Out Noise

Long time Lurker....

I have a noise that I was originally convinced was a center bearing. This weekend I replaced the center bearing and 3 U-joints. I also replaced the rear differential oil. The sound remains...

The noise almost sounds like tire noise, almost too high pitched to be a bearing. I just had driver side front wheel bearing replaced, so I know what that one sounds like...

2006 DCLB 4x4 4L SR5 with LSD
Fire Stone Desination LE2 stock size
160k miles
No mods
New OEM Center Bearing and 3 Spicer U-Joints (freshly greased)
New wheel bearings on the front wheels less than 1000 miles ago.

The sound comes in at 55 and increases with speed. It does not change with throttle or if the transmission is in neutral. From the driver's seat it sounds like the sound is coming from the rear of the truck. The noise does not change if the truck is turning.

There is no play in either of the rear wheels or in the rear differential flange.

I put the truck up on jackstands today and ran it up to 60 with the wheels off of the ground. No noise.

I could not hear the noise on gravel.

I'm starting to lean towards tire noise but the tires are not aggressive at all and they look perfect. They probably have 15-20k on them.

Anyways this one is confounding me and with spring here I am going to start towing the boat again and want to make sure everything is safe. Any help would be appreciated....

 

Rotate the tires and see if the noise moves.

Or borrow tires from a Tacoma buddy and see if it changes/ends

 

I rotated the passenger side tires and it made no difference.

The noise sounds kind of like what you hear when you pass a semi.

 

Full balance and rotate today. The mechanic said the tires looked in good shape.

I starting to think it is a wind noise. I guess I will find out if something blows up.