Ya know what, I just now thought of it. I wonder if it's the viscus fan clutch ... try taking the fan completely off and running it to see what happens? Sounds like it resonates, like a twangy thin steel fan.

 

It's all been replaced though and it does it after driving a little without the belt on

 

Fan clutch activates when the radiator gets warm, and might spin while there's air being pushed through the radiator. Does it make the noise with the belt off and engine idling? Cause if you're driving without the belt on, I can see the air from the radiator turning the fan making noise.

Also I guess if you're going go go through the work of pulling the engine apart to figure out the noise, I guess it's worth taking out the torque converter bolts before you get too crazy. That way you can 100% verify that it it not coming from the torque converter or transmission. Just pull the starter, and take each bolt out and then slide the torque converter back into the transmission a little so that it clears the flexplate.

 

Well i replaced the torque converter and flex plate thinking that might be the cause and still no luck. Took it to the shop and the still have no idea... anyone have any other ideas?