replace the mirrors inside the unit for H4 better option and yes the system can take it look at de Older MP3 500 / Gilera Fuoco it got 4 headlights
When i do a conversion i will glue in H4 mirrors in to the older H1/H7 mirrors so you are able to adjust the light as normal with the adjustment screws
there is a how to here some wher i've done years ago H1/h4 problem solved or something like that can find it right now have to many threads made