Use an OEM filter that flows well. The AM seem to not be any good. There will be less vacuum to deal with in the filter.
Make sure there is a good seal between the carb and filter. Make sure both face are flat. Certainly make sure you aren’t using the new style replacement carb with the old style filter. The filter won’t sit flat on the carb at all, the comp horn will hold it off the carb.
There is a gasket included for the carb in the OEM kits. The old models used it between the carb and boot back in the day. See if it fits between the carb and the AF. I haven’t tried to use it, but it should fit.
Clean filter and tape the seams shut.
Sharpen your chain so there aren’t as many fines to start with.
Add a Frogzskin adhesive backed screen to a hole you drill on the Flywheel side of the air filter cover. It will reroute the air flow and decrease the amount of dust the entire airbox air breathes in by redirecting flow. I know it makes little sense, but it actually works.
That’s all I got.