New to the forum, did some searches but didn't find anything.

Here's my issue ('03 Dodge Durango, 4.7, 4WD, Auto)

Between 50-60 mph there's an intermittent click (or tap, or tick) noise.
Sounds almost like a soft antenna-loose kind of noise.

Put it in neutral, rev the engine, the noise does not speed up, or slow down based on engine speed.
Noise is the in OD or Drive.
Road is straight, not overly rough .... basically a normal country road.

I've looked for obvious of something loose, don't see anything.

Anyone have any ideas?

 

Is it only when hitting bumps, or does it do this on smooth asphalt? Might be the front axels(s). Check the other thread in this section relating to clicking in the front.