ORIGINAL: Antique
Pull the hub and use a #21 drill to SLOWLY drill the bolts out from the back side...I would highly suspect a company that could not get a prop hub off an engine that they put together....[>:]
No need to pull the hub, drill the broken shank with the #21 drill bit, then purchase and use a #2 easy out turning turning it counter clockwise, the shank will come right out. You must drill the shank straight in order to not damage the threads.