flickering lights 66 dart

my 69 Dart does the same thing... sometimes the voltage will just instantly go way down, radio will shut off for a second, tap the gas pedal, poof, everything gets bright again... I have changed the regulator more times than I care to remember, finally going to an elctronic one, changed to a dual field altenator as well.. that helped, for a short time the lights and all stayed constant and steady... but in a very short time we are back to the same issue.. it keeps me from driving the car at night for the most part, and is actually a pretty irratating problem.. I have no idea what keeps causing this.. eventually i am gonna get pissed off and rip every single inch of wiring out of that car, and spend years and a fortune putting all back together LOL ... any other ideas as to what causes this would be appreciated...