12v trucks started in 55 - the floor starter went till at least 59 - whatsa matter w/ the floor stomp start? coolest feature you got! if you're wanting to change the starter cuz the truck is 12v now, the 6v starter will work fine on 12v
I imagine if all you want to do is change the foot stomp for the v8 style ign sw, you could get a later starter [60+] and bolt it in, change the sw - don't know about the bendix and ring gears, but I'd expect'em to be the same on any full pressure 235 - GM didn't waste money changing design details year to year - might even be able to just swap starter motor cases to get the one that mounts the solenoid
Bill