I'd check with a machinist. ÂÂ
Find one that will work for beer.
If it wrung the head of the bolt then you are probally not going to back it out easily.
I just did one and mine was a SOB to get out.  Now I need a tap to clean the threads, 10x1.25 I think. ÂÂ
And a few good ideias on crank keyway repair.
I start a new thread on this repair, Not intending to Hyjack... JB Weld to correct the damaged keyway and some Loc-tite 609 on the shaft.ÂÂ
Loc–Tite # 609, Cylindrical Type ( Green ) high viscosity / high temperature, and # 680, medium viscosity / high strength. This is used when you must fill and ‘ voids ‘ or wear on a shaft when mounting a gear or pulley. It is usually not necessary to use any heat on this type to make it release. Remember to clean the oil off the mating parts before using Loc–Tite. Acetone or plain alcohol usually works well.Looking into possibly drilling and taping the (Crank / pully) mating area opposite the keyway and adding a set scred to take some of the load from the key.