spark and no spark

OK great............ so let's get clear on this. You have the voltmeter clipped to the coil + and to engine, and using the key you are only getting 8V or so cranking? That is low. That probably shows a problem in the key switch bypass circuit.

What I would do is clip to something in the engine bay that gets you "battery" that is starter relay stud, or the starter stud. Crank and read, see what you get. If you have 10+ there but only 8 at the coil, then the problem is in that area, ignition switch, switch connector, or bulkhead connector, or a problem where wires come together at ballast resistor connections

You have a shop manual? Wiring diagram?