Yeah, I should have mentioned that. The smaller the stem to worse the vibration. I set a rear stop so all the valves end up in the same spot. And I keep the valve head as close to the Chuck as I can. That helps a bunch. I need to look and see what insert I used and that thing eliminated 99% of the vibration issue.
I leave the valve .002-.003 big and run a file over the OD to size it and run them.
