I have a 1975 pickup. I have the distributor and coil/ignitor for a 1980 pickup. Is there anything else that I need to use it for my '75? Also, there are 2 wires coming off of the coil/ignitor. Haynes shows the BY wire going to the ignition switch. The other is black. Where does it connect? Is it a ground? Haynes shows it going to the distributor. thanks much for any help.