Not necessarily- - - - -just take a few precautions to keep the shavings out of the timing cover. Pack rags tightly around the crank snout or use masking tape or duct tape to seal the gap, stand the block up on the flywheel or the bellhousing on the base of a big floor-mounted drill press, and drill a 25/64" hole about 1 1/4" deep in the center of the crank snout. Then use a 7/16-20 plug tap to thread it at least 1" deep. Then rent a harmonic balancer push tool from a local parts store and install the balancer until it bottoms against the timing gear.
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!