If the motor and flywheel are '57 vintage then you need a 12 volt starter. Get a 12 volt starter for a '55-59 chevy pickup C-10 or Apache. The starter motor will be 12 volt, the pinion will be correct for the 168 tooth ring gear used '55-'62, and a '55-59 truck starter will be a foot-masher. The 53-62 235 car starters had electric solenoids.
hope this helps
chip