I have done dyno runs on performance engines up to 7K RPM and 700+ HP on run stands with solid mounts. I haven't noticed any problems with vibration or torque reactions. It's highly unlikely a stovebolt engine will cause any problems.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!