That type of balancer has a squared-off shape so the crankshaft can be turned with a 3/4" square drive ratchet. The taper on the puller jackscrew needs to be 5/8" diameter or smaller to prevent hanging up on the balancer before the thrust gets to the crank snout.
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!