So far I have tried US Gear and Motive but still have a howling noise from 55 to 70 mph in 5th or 6th gear.

Am I stuck with this noise that I hear is inherent in the Moser 12 Bolt plus the fact the F-Body is notorious for gear and other noises, or are there any 12 Bolt gears that are quiet assuming the installation is correct?

Backlash on gears is set at.007 and the pattern looks good.

Note: I am almost dead silent from gears 1 through 4 (I have a six speed manual transmission) but the noise only occurs at 55 to 70 mph with rpms around 2,000.

Appreciate your input.

Thanks!