Robb 79SC

While replacing the fan belt on my '79 SC I managed to cross thread the nut that holds the outer pulley half to the shaft coming out of the fan/alternator. I think the shaft threads can be dressed up but the nut threads were destroyed. According the the Pelican Parts and Performance catalogs, that nut is no longer available but one for the 1982 and newer is. Does anyone know if the 1982 nut will fit a 1979? If not, any suggestions on how to fix the problem without having to replace the alternator? Happy Holidays and thanks for the help.