The Stovebolt Site Forums The Shop Area General Truck Talk Trico wiper shaft and arm question

Hi, i have a Trico wiper motor model KSB-404-IG, i made one good motor out of two but need to know if I have to proper shaft for a 1939 chevy. I'd like to know what kind of an arm I need to order to put this back in operation. Any help is greatly appreciated

1939 Chevy VD 1.5 ton flatbed with original 216