You have yet to explain how the Chrysler Gold box I had would show 1 degree of retard at 10k. With a Chrysler magnetic trigger. Was it the box. The distributor? Some of both?
To play Captain Obvious, the right answer is "All of them." Any point in the system can take timing out, and when that happens, ain't nothing putting it back in. So for a system to hold the timing that steady, the chain must have no weak links.
Sometimes that point is even a component in a system. Hypothetical example: A particular CDI box might have very little retard with a points or optical trigger, and you have a particular Gold Box and magnetic pick-up distributor that has very little retard, but pair the exact same CDI with the the distributor from the Gold Box combo and you suddenly get 6 more degrees of retard. What happened? The magnetic pick-up conditioning circuit in the CDI box just didn't react as fast as the one in the Gold Box. (Maybe running the Gold Box to the points trigger would get back some of your timing!)