it is probably the same thing for all sohc. i updgraded my sealed beam headlight today using an H4 from an 82 650 a have lying around. it took the headlight glass part and the retainig ring that come with it and "voila!" a 30 minute upgrade that did a big difference. i installed a Sylver star bulb while i was at it.
i know some have ask for this kind of conversion before, now i did it with honda parts( i think)
sorry, i forgot to tke pictures, but it is as simple as changing the stock seal beam. the 650 ring was a bit thinner than the 550 one so it can fit the 650 headlight.
if you have questions, pleaze ask!