250's drive the outer ring of the harmonic balancer with a bonded rubber ring. That outer piece also contains the grooves for the fan belt(s), and they're notorious for breaking the bond and letting the balancer ring slip. I guarantee it will happen again, no matter how many witness marks you make. Change the balancer- - - -they're dirt cheap on Ebay.
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!