Here's a way to test CD box function and coil output.
Disconnect the distributor from the box. The box has a lead for points type ignitions. When you install the box, leave a short length of the points lead pigtailed and taped for diagnostics like this. Connect a test lead to the points lead and park it someplace where it won't inadvertently touch anything. Leave the coil connected. Put a spark plug on the coil output plug wire that normally goes to the distributor. Grip the base of the plug with a vice grip, lay the vice grip handle on the engine block with the plug tip facing you so you can see it.
Turn on the ignition so there is power to the box. Tap the points lead from the box to a ground momentarily. In a points ignition, the spark is made when the points open. Here, a spark is made when the points lead briefly touches a ground (simulating points closing, then opening). Plug sparks. Box, coil, and wiring are good.
Distributor phasing. The distributor rotor needs to point to the #1 plug wire when the #1 plug fires. Since the crank, and timing pointer rotates twice for each distributor rotation, it's easy to get this wrong. The engine coughs and pops through the carb, but won't start.
With distributor cap on, put a mark on the distributor housing right under the #1 plug wire with a magic marker. The rotor tip should point to this mark when properly phased. Take distributor cap off. Using a breaker bar and socket on the crank bolt, rotate the engine until the #1 intake valve opens, then closes. Keep rotating the engine until the crank timing pointer is at 12 deg BTDC (or wherever you set your initial lead). Rotor tip pointing to the mark you made? When it is, the distributor is properly phased. If it isn't, reinstall distributor until it is. Use an
oil pump drive primer tool, or same size socket on 1/4" extention to rotate the
oil pump drive to help seat distributor in
oil pump drive.