The ones in a stovebolt crankshaft flange- - - - -They just happen to be exactly aligned with the three pairs of connecting rod journals. If a crankshaft has been indexed incorrectly during a previous regrinding job, a machinist who knows that little tidbit of information can get the journals back into the proper 120 degree separation by using the dowels to index the crank as it's ground to a smaller undersize. That's also how I'm planning to get the stroker shafts I'm making as accurate as possible when I increase the stroke and grind the journals to a smaller diameter. Just a heads-up for anyone who is going to get a crank reground anytime soon.
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!