It was amazing how difficult it was for me to fit a H4 HID in the lower position...spent lots of time moving and tying back the loom in order to make it work, and that was just the bulb. Yes, the H4 is a little deeper because of the attached solenoid, but I had to hide the ballast in the side fairing to make enough room.
Long story short, the wider the reflector, the deeper it will be, generally speaking, so I would measure the depth carefully. I wish you all the best, as I had *planned to look into doing this myself.
2009 KTM Adventure