Has the engine been assembled for a while, or has it been rebuilt recently? I think I would have investigated things a little further by dropping the oil pan and looking at the position of the timing gear before doing a butcher job on the balancer.
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!