4-speed chatter problem

That does not sound good.

I got a 833 once that had the pilot shaft cut and was terrible. My crank was right with the oilight bushing and had to get a new shaft.

Sounds like you do not have all the right components and maybe steering Brewer in the direction you want to hear. Perhaps you need to re-evaluate what you have and decide to fix your crank or go Auto.

I've done the bearing with several conversions (including 5&6 speeds), it's a viable option. Just make sure the shaft isn't hanging up in the crank.