This is a pretty homemade trick i just did today,nothing special, i have a dougnash five speed with the external hurst shifter, like muncies, richmonds, etc.. well at higher rpms in any gear my shifter would make this terrible rattling vibration noise. I have replaced all mounts, clutch, tranny rebuilt, had flywheel and clutch balanced, and it wouldn't go away, finally after talking to other hurst owners they said theres did it some too. So I figured those shifters are just naturally slighty noisy. So today i went out to fix it. I took off the chrome handle from the shifter, at the bottom of the shifter it took some slightly thick rubber and rapped it around the bottom of the shifter handle, where the handle meets the shifter and held it on there with some electrical tape, rapped it all around, you have to use skinny pieces because it can't cover the shifter holes( where the bolts go through) then i put it back in the shifter, had to use a little longer bolt on the bottom hole, then bolted it back together, now the rubber acts as an insulator from the shifter and the handle.and I can barely hear the shifter ratttle at all, just a tiny bit. Worked good! That rattling was the most annoying thing ever!