distributor wiring

Hey guy I need some help I have a 1966 GTO. Switched over to HEI Ignition. Does any one know what wire the tach. signal is for the factory tach? I am also wondering the wire at the firewall with the slotted connector is this for the dist. batt + one black wire and one with the white insulation? Is This a resistor wire to drop the voltage down for the points?

Thank Jon