72 c20 stripped master cylinder stud

[chevy72blu]

Tonight I attempted to replace my master cylinder and all went well until the last (driver side) bolt. One of the master cylinder studs stripped while popping the support bracket back into place. Does anyone know if this is welded into the booster or if it is a threaded stud? My hope is that I can use a pair of vice grips to remove it and thread in a new one. I'd rather not replace a perfectly functioning booster if at all possible.

Thank you for your help!