In my other (recent) thread I mention that I have a '59 Fairlane 292 in a 1930 Model A Coupe.  Since there isn't a ton of room I was thinking of sourcing a smaller battery for it.  Does anyone know the minimum CCA requirement to get a Y block spinning to start it up?  All this thing has is a couple of electric gauges, headlights, turn signals, and brake lights.  I hear some people run tractor batteries, etc.  

Thanks.