Reply to "spark timing"

Change the plugs. There is only one ignition system I know of that will fire and clean up fouled plugs.
That's the Pantera-Electronics. The Ford, Petronix or the MSD will not fire fouled plugs.
You might want to use the AF-42 Motorcraft plugs right now until you have the other issues solved.
It won't foul up as quickly around town.
On the other hand it probably will work a little like an rpm limiter above 6,000 rpm.
It's a little hot for that engine with 36 degrees of advance BUT you will hear them blowing some of the carbon off of the valves if they are loaded up.
AF-32's are really what you want when the engine is right.