electrical, possible alternator problems

:?:Ever since I've had the bike it has seemed tp run better with less electrical load. It runs better and accelerates faster with the headlight unplugged. It has progressed and definately has a miss that goes away with the headlight unplugged at higher rpm's. Now from what I've read here the early 750s were plagued with weak alternators. But I know that in austraila, new zealand and canada the xj750s were used for police work. I know that they had more electrical load than civilian bikes too, so what did they have that the standard bikes don't?
Can I have it rewound for more output? Are the brushes different? I'd like to convert it into a solo touring bike but its just one of the bug-a-boos I'll need to iron out.
Also, I've got led's mounted to my windshield with standard 1156's in back but the flasher dosn't work, I've got resistors to add to the system to increase the load for the flasher but I'm not sure weather to wire them in series with the leds or to the flashers or in parrelel to ground. Any Ideas? thanks.