8 Volt Antique Car Battery. They each show about 825 volts. This is for a 53 ford f100 with the 239 flathead.
I am using an 8 volt battery in my 6 volt positive ground stock set up. The 6 volt starter will work OK as it will only be getting the 12 volts for short periods of time. Are you trying to find Vintage Part for sale online.
Antique Auto Battery also offers 12-volt restoration batteries as well as 8-volt batteries which can be useful to give additional starting power to a 6-volt system but must be used with voltage resistors on susceptible electrical items such as radios lights and blower motors.
When jumping with 12 volts have all electrical items such as headlites radio heater in the off position. 8 Volt Battery Chargers and Maintainers. Looking for Antique Volt available on sale. Avoid overcharging with a fully automatic 8 volt battery charger that properly maintains your battery even in long term storage situations.