Are you 100% sure it the noise isn’t coming from the new gears? I’ve had aftermarket gears that were a lot noiser than stock. Might not have been set up perfect.
That is what I am trying to figure out today. Draining the fluid in the transfer case right now to see if there is any metal. Pulled the front driveline and jacked it up on jack stands. At 40 you can hear a vibration, but cant say for sure where it is coming from. Almost seems to the rear end. About to put it all back together and when something breaks we will all know then what was making the noise!