When you repeatedly grounded the coil neg terminal like morse code you had to hold the coil secondary wire VERY close to ground to even get a spark, correct? Jump 12V from the batt positive to the upstream side of the ballast & see what you get for spark(key on) then repeat w 12V to the other side of the ballast & if you then have a better(blue) spark see if it will start & if not jump 12V to the point of the pentastar plus(the above) to the ballast & see if it will start.