I have 1948 chevrolet 3100 in line 6 I had a over heating issue changed radiator and thermostat went to start and now it's barely turning over changed battery but still having trouble turning over need help.

 

Check your battery cables for tight connections and no corrosion at both ends and both cables. Are you still running 6 volts? Are you still using the foot pedal starter? If so check the switch for burned contacts.The starter may also need a good cleaning and new brushes.