The small overflow pipe on the inside, bottom of the tank is what the lower crankcase breather tube connects to(short rubber hose, just long enough to make the connection).
Not sure what the filtering box on the head is about. There is an emissions filter mounted under the battery box, could that be it?
The K8-F2 750 manual is somewhere on this site, pretty sure. There are some good pics and diagrams in it that show all the hose, line, and emission routings. If ya can't find it, I can burn ya a disk and pop it in the mail, or extract the relevant page(s) and email 'em to ya.
