I did a Hella housing, Sylvania H-4 bulb, dual relay headlight conversion last year. I had previously converted the original generator over to an early 60s GM style externally regulated alternator back in the early 80s, probably 37 amps or so, maybe less. The headlight conversion was a really really good improvement. That being said, it was too much for the low amp alternator which was not able to keep up. Swapped to a Tough Stuff 100 amp alternator and electronic external regulator (was not looking to mess with the wiring but the mechanical regulator will not work with that kind of draw, keeps cycling on and off. The heavy duty electronic external regulator does not suffer that issue). That did the trick.
