Don't know exactly and I had already done the MAD bypass years ago. A few months ago I changed to an MSD box, eliminated the ballast and wiring from the harness, and tied ignition 1 and 2 for 12v during cranking (for MSD). After doing that I experienced a pulsation in voltage regulation at higher RPM. I determined I had about a .75 volt drop through points in the dash before coming back out to the regulator (that I could not easily remedy). Putting the VR on a relay to bypass everything south of the bulkhead cured the problem.