if you need to replace the regulator and rectifier, I highly reccomend going with a more modern combo unit. My backround is more in the honda SOHC bikes, and lots of those guys buy a used reg/rec combo on ebay from a cbr600rr for around $25 and wire that in....so many guys have done it there's a wiring guide/how-to for the SOHC-4's
probably wouldnt be TOO hard to figure out how to wire it in...