All 235s from 1955 to 1962 (last year) had 12 volt electrical systems & starters. The car engines had electric solenoids. Just turn the key and it starts.
The trucks up to '60 had foot-pedal starters. In '55 Chevy went to 12 volt for all their vehicles. They changed the # of teeth on the ring gear from 139 to 168 and also redesigned the starter pinion to match. They kept the foot pedal in the trucks. In 1960-61 chevy started to equip their trucks with electric solenoid starters just like the cars got in the early '50s.
Verify your 235 is a '57 model. I assume the flywheel is a '57, has 168 teeth and expects a 12 volt starter. So you'd need a 12 volt starter. The truck's ign switch should only have a "off" and "on" position, no "start" position. So you have to use a 12 volt foot masher unless you change the ignition switch and run the "start" wire to the starter solenoid.
So count the teeth on your ring gear to be sure. 168 teeth means you need a 12 volt starter. 139 teeth means you need a 6 volt starter.
If I may digress a little, I've been hearing that you can run a 6 volt starter on 12 volts. I would have to disagree. YRMV, but I tried running my '54 235 6 volt electric solenoid starter on 12 volts for 2 years. I burned up brushes every 4 months, burned up the field windings, burned up a solenoid, ruined a pinion, and ate through TWO ring gears. And the motor didn't require a lot of cranking to start. After I went to a 1960 12 volt ring gear and starter, I haven't had any problems.
hope this rambling helps
chip
