Ganesh,
I wrote about the same subject in another forum.
My 1963 HOLDEN was running it's original generator.
Brand new wiring, relay box etc. it worked a treat.
Until I drove it at night in the City.
Just having the headlights, turn signals and brake lights operating at a low engine speed, combined with stop/start driving flattened the battery in no time.
I have since fitted an alternator and have yet to see any problem at all.
Make sure that your battery and voltage regulator are functioning 100% before swapping over to an alternator.
