Fastest American built muscle car leaves open to a lot of cars.In my mind the only true muscle car of that era not being a high production built car but was street legal and had "ZERO" competitiors was the 66 Shelby Super Snake,tho limited in production absolutely no other cars could touch it.
I think if you drove one or even a new Shelby 500 with the auto trans you might rethink that issue rather quickly,removing parts to lighten the overall powertrain to increase traction and performance.I could easily have more fun with a paddle shifted auto trans than a 6 speed clutch and pass by...
I think you have a bad regulator/rectifier if that pos cable melted.I had a 900 that happened too and that's what after swapping parts out I found to be the problem.Yours might be tho different,just sayin you might consider that a part of the problem
If I recall and I could be wrong the 83's had a electronic ignition,Could be the pulsing coil or ignitor is going bad,but probably just old coils that might need replacing on a 30+ yr old bike,good luck