Diagnosing Distributor - No Spark Chase

Its either the ignition box , or the ballast resistor. Or at least I would start with these. When I use the mopar electronic boxes, I always carry a spare as with the ballast resistor. Had to many go out over the years. So First check the ignition box, go but a cheap one first to see if it solved the problem. If neither of these work and you still have no spark then I would try a distributor. However I have only had one magnetic pick up go bad in 30 plus years of messing with mopar distributors ( maybe i have been lucky)