[BAracer]

Welcome

I have a few Scaleauto R chassis, and if the Viper has come with a red Scaleauto pod, it's a good rigid foundation for a build.

How is the mesh between the two gears? That is often the source of noise. I set mine up so that if you hold the pinion still, there is just a small amount of movement in the anglewinder gear. I do that check a number of positions of the anglewinder gear to check that it's not warped. Basically I am making sure the two gears are not being forced tightly together whilst rotating.

If there is too much play between the two gears, then that can also generate noise as their clunk against each other at the moments between acceleration and braking. 

I have never read that you cannot mix and match different manufacturers gears. In terms of replacing the AW gear, the trick is in finding alternatives of the same diameter, or very very close to, your existing gear, so that you are not introducing more meshing problems.