Chrome Box?

I have used the similar Crane XR700 on 3 cars (originally Allison). It has a similar optical pickup (3 wires), but their own "ignitor" box with 3 power/coil wires. Your optical pickup probably failed, as did one of mine. Replacements cost ~$50 so I fixed mine. I just picked it apart, looked up the part numbers and ordered a new infrared emitter and sensor. Worked fine, but too much effort to do again. The 3 wires are +5 V, gnd, signal.

Since you have the "ready to run" distributor, as I do for my 273, why go back? I expect your old B-W box still requires the ballast, as does my XR700. Only later, in GM's HEI, did they learn how to control the coil current so they didn't need a ballast.

I suspect the optical pickup is more precise. I may consider using it with an HEI module. That requires providing +5V power and shifting the output signal to cross zero (series capacitor?), so probably a custom circuit board and a definite back-burner project. 66plyValiant is correct that the optical pickup wiring is similar (or identical) to a Hall-effect pickup.

If you can develop a spark timing controller in 1 week you will give MSD a run for the money. Their's is $$$. Search the GM 7 or 8-pin HEI module, which allows timing control. The Holley Commander 950 interfaces with it, as do other engine controllers. You could do similar.

Re the Mopar boxes. If you look on rockauto, it looks like they supply the 4-pin box for all years now, at least the photos show that. As I understand, the early boxes needed a ballast for the coil and another ballast for the box itself, hence the dual ballast resistor. Later, they were able to eliminate the ballast for the box itself, so went to the 4-pin box and single ballast. I think you can connect a 4-pin box fine to a car w/ dual ballast and 5-wires, it just won't draw any current from the extra wire (grn/blk to pin 3, I recall) or from that ballast, as you can see in the post by 66plyValiant.