225 Slant no spark

I just went through a somewhat similar experience... Try and hot wire it by running a wire from the positive battery terminal to the positive post on the ignition coil and use a screw driver to connect the solenoids on your relay. This bypasses the wiring of the ignition switch and if it works, I'd double check the connections going into the firewall and consequently, the other side under the dash.

Keep in mind, I may be talking out my *** as I don't have anymore experience than trying to fix my 70 dart slant 6 that I've had for a little over a month.

If you're still running points, I would double check those as well and see if you're getting any spark at them.