http://www.common-motor.com/honda-450-halogen-headlight
We have upgraded the headlight on our Honda CB450 to a modern H4 style halogen bulb. The new headlight lens allows for easy replacement of the bulb which is much brighter than the stock sealed beam and are readily available. We run the proper 35 watt bulb to keep from over working the charging system, while providing more light than the anaemic stock sealed beam.
Halogen headlight conversions are available Honda CB350, CB360 & CB500T as well.
http://www.common-motor.com/honda-cb-headlight-lens-bulb
http://www.common-motor.com/honda-cb-headlight-bucket-bulb