Placement of the ballast is probably the lesser of the potential problems. There are other technical difficulties like the dual-filament H4 bulb which would require a moving mask or apeture for the high-beam mode, and the basic reflector design. I think that one would might end up having to replace the entire housing assembly.
Here is an excellent technical resource:
http://www.danielsternlighting.com/t...nversions.html
And here's a motorcycle kit you could try:
http://www.cqlight.ca/product_info.php?products_id=90
Let us know what you think ....
