Help Please
Back when MSD was made by Autotronics, this was in the instructions in CAPITAL LETTERS.
In fact they supplied all the pieces to make it easy to revert to the original ignition if there was ever a failure with the MSD 6.
The instructions would be like this for your '72. White wire only used with points distributor.
You can do something like this with a terminal strip,
or a male terminal with hole that can be bolted to the original coil wire like this.
Then insulate the exposed metal with heat shrink tubing or whatever you prefer.
Another approach is to insulate and secure the original wire's ring terminal, and put a piggy back the MSD 'on/off' wire to the the ballast resistor.
Piggyback terminal.
There's no reason to bypass the ballast with an 6A unless the resistor is broken.
Back when MSD was made by Autotronics, this was in the instructions in CAPITAL LETTERS.
In fact they supplied all the pieces to make it easy to revert to the original ignition if there was ever a failure with the MSD 6.
The instructions would be like this for your '72. White wire only used with points distributor.
You can do something like this with a terminal strip,
or a male terminal with hole that can be bolted to the original coil wire like this.
Then insulate the exposed metal with heat shrink tubing or whatever you prefer.
Another approach is to insulate and secure the original wire's ring terminal, and put a piggy back the MSD 'on/off' wire to the the ballast resistor.
Piggyback terminal.