Is there some reason not to drill & tap the crankshaft and eliminate the possibility of damaging the balancer? I made up a tooling set to do that, and made it available to any stovebolter who wants to use it, for a modest deposit and rental fee. It's made the rounds of a couple of bolters already, and worked well enough that they were pleased with the results.
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!