The 8V battery will create many more problems than it solves. The cutout relay voltage must be set to 8.5 volts, and the voltage regulator adjustment needs to be set to 9.5 volts while the generator is charging against a fully-charged battery. Your points and all the light bulbs in the system will have a dramatically diminished lifespan due the the fact they're exposed to approximately 25% more voltage than they're designed to work with. I grew up aropund a shop where we did top-quality charging system work in the 50's and 60's, and Dad absolutely refused to set up a charging system to accomodate an 8V battery. We did do a LOT of total charging system overhauls after car owners learned the hard way about using the wrong voltage battery! The only proper application for an 8 volt battery is in some antique farm tractors which have an electrical system designed to use that voltage, and virtually no electrical accessories.
Jerry
