Help with Flathead Ford F-4 Truck

Uh, the generator will need to have some work done to convert to negative ground. Otherwise it will charge the battery dead assuming nothing goes up in smoke.

I'd take it one step at a time. Get it running somewhat reliably, and then if use justifies it do the 12VDC/Positive ground conversion. I'd simply put a second one of the same batteries in series with the one just bought rather than buying a 12 volt battery.