Will report back.

 

Depends on what the noise is. Original Muncie 4 speeds had a lash absorption plate pinned to the front of the cluster gear. It was spring loaded to take up the lash between the main drive gear and the cluster gear. Without that, the cluster gear rattles like loose ball bearings in neutral, even on a fresh rebuild. An M22 rock crusher is even louder than M20/M21. As long as there's no rattle when its in gear and under load, you should be ok.