I’ve built and installed two. One customer drives his with a 3.54 and loves it drops the rpm to 2700 or so at highway speeds. He does not complain about the noise but his car is not that quiet. The other guy did mention the gear noise but his rear end makes noise as well. I told him that it sounded just like most hemi boxes anyway. I will be changing his rear gears so I guess we’ll see about that more.