Fuel or spark problem?

I have a 67 Dart with a newly rebuilt 318 with a small cam (little lope at idle but still enough vacuum for my power brakes), and new street demon carb (thermoquad type). Engine ran well for a few months. Idled well at 800 rpms and would do a burnout with my 2.76 gears. Few weeks ago engine would just flatten out with a continuous stutter over 2000 rpms and then would not want to idle either. Engine would often stall when coming to a stop sign. Sometimes when flooring the accelerator car would stutter then surge, going back and forth between stuttering and accelerating properly. I replaced my fuel filter which did have a fair amount of very fine black particles in it. It did not help at all. Now the engine is hard to start and will not idle at aIl. I removed the air mixture scews from the carb and shot carb cleaner in them. Replaced them at 1 3/4 turns out but this did nothing. Car has a Pertronix Ignitor 1 conversion which has performed well. Replaced the coil with another pertronix coil I had but no difference. Thought electric choke might be closing but it is open. Mechanical stock type fuel pump is only a few months old and the fuel filter is full of fuel. Looking for a logical plan of diagnosis without buying a bunch of new parts I don't need. I guess hooking the fuel line to an external gas can would be a start to see if fuel sender sock is plugged? Any help is greatly appreciated!