1972 dart - stopped running while at 50 mph ? no warning

Well if you have spark at the coil, you need to get it to go through the distrubutor cap and out the spark plug wires.

3 things make an engine run:

1. Compression
2. Ignition
3. Fuel

Simple especially with a points distributor. Try putting in a new set of points and condenser. Spray down the top of that distributor with wd-40 then blow out with compressed air. dry dirty mess in there. Should be clean and lightly lubed.