Pride gone... asking for help

If you test the rockers and the cam on that valve is such that it should be closed there WILL be some looseness in the rocker. This engine has a mechanical cam and a small amount of lash is normal when the valve should be closed. It should be somewhere in the .015 to .020" range for that engine if set right; normal wear will make it bigger if no one ever adjusted it. If the 'looseness' you find is this small, then the valve is not necessarily stuck.

But... on an engine that is this old, it would be possible that the the valve guides are sticky and the valves are hanging not closing quickly. AND, I would bet on some of the rings being stuck at this age and lack of running. You need to get it running a bit before you can evaluate the rings and valves sticking. If you want to, spray some carb cleaner in the valves springs at the valve stem and then crank; that will work some cleaner down the guides and loosen any gum in the guides. (It will also finish off the valve stem seals, but they are dried/cracked/shot to heck by now anyway.)

I am not convinced that you yet have good spark, based on your writings. Putting a spark plug on the end of a plug wire and looking for spark in open air across the gap is a useless test. It only takes a few thousand volts to jump the small spark plug gap in open air, but it takes 20,000 volts or more to jump that same plug gap in a compressed fuel air mixture.

Go back and place the spark wire from the coil so that the open end of that wire (when pulled off of the cap) is about 1/4" to 3/8" from metal, like the inner fender or the valve cover. Then crank and see if the sparks jump that size of open air gap with a hot looking blue spark.

And you said you have 6 volts at the coil; that is good under certain conditions but not others. When the engine is cranking, the voltage at coil + should be only 1 volt or less than the battery voltage when cranking. So measure your battery + while cranking and then measure the coil + voltage when cranking and find the difference; let us know what you find.

BTW, what ballast resistor did you put in? Many ballasts are wrong for the Mopar system.

Did you scrape the metal under the ECM clean so that the ECM gets a good ground? That is vital.

Measure resistance of each spark plug wire and the coil spark wire end-to-end; they should typically be in the 5-10k range.

When you try to start, use 1/2 tablespoon or so of FRESH gas dribbled down the carb at a time. That amount should allow the engine to fire and run for 1-2 seconds.