I can only share what I've read - and then remember (which is far more difficult).
Others have had problems with non-CB750A regulators - because the regulators weren't "matched" to the field coil.
It is my understanding that the field coil of other bikes do not require as much current, and some regulators just can't deliver sufficient current. Low voltage was the result.
I suppose if you do enough "homework", and determine that the field coil demand, for example, on a later bike was comparable, then I see no reason why it would not work.
