Set the idle screw to the RPM where the shake is most evident, then start disconnecting spark plug wires one at a time to make sure all the cylinders are firing. A tachometer and a vacuum gauge will help isolate a cylinder miss- - - - -little or no drop in RPM and/or vacuum means you've got a weak cylinder. You can also run the engine for short time with the fan bet removed to rule out an unbalanced fan, or problems with the water pump or generator.
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!