I would NOT attempt to run any Mopar box without a ballast. Use a different ignition, and if nothing else, use a GM HEI module. Contrary to some you can run an HEI module with a stock Mopar coil, although going to a more modern "e core" coil is for sure better. But yeh. Basically just connect all the wires together. Your old coil + wire can then become the tap off point
BUT there is really more to it. With stock wiring, "that point" that is the "ignition run" supply line suffers from VOLTAGE DROP because of the infamous ammeter/ bulkhead connector wiring. Consider adding a relay. Identify the "run" wire coming out of the bulkhead, cut that wire apart, and use it to trigger a relay with the power contact fed from say, the starter relay "big stud" through a fuse or breaker. Then feed the output contact of the relay to the IGN run terminal of the ballast (originally) or just "into the splice" if bypassing.
If you have not done so, go over to MyMopar and download a free service manual. You may have to accept Plymouth vs Dodge or vice versa.
It is ALSO important to understand that the key "run" line GOES DEAD during start, and that the IGN2 bypass/ brown wire that originally connects to coil + side of the ballast MUST be kept "in the splice" as it supplies starting voltage during cranking. THIS IS a DIFFERENT contact separate from the yellow "start" circuit
