Seconding (???), Downunder's and MinnFlyer's posts...

The T.H. is no more prone to vibration than any other engine.

As indicated, balance your prop & spinner.

You may also need or want to re-do your engine mount. It may be contributing to this.

At worst you can also utilize a Dubro anti-vibration mount.

When I put these on planes, almost no harmonic vibrations get translated back into the fuse.

If you put your hand on the fuse you can barely feel the engine running at any speed. This will make your plane last longer too.