what is the difference between a 180 and 185
I wouldn't bet my left nut on it (or the right one for that matter) but my recollection is that you are correct - the C180 and the C185 share the same airframe. The 180 I used to fly had the same engine as the C182 (230 hp ?) while the C185s had 285 and 300 hp IO520s.
Dr 