thanks mark, someone posted the Hangar 9 Beaver @ 231mm which is a shade over 9" I think that would work. I need to pull the spec on that motor, seems the centerline was 220mm (8.66") and 207mm (8.14")was distance from rocker of one cyl. to rocker of another. sure would be nice to have it in that super cub. I'm sure the 1/3 World Models super cub would have no problem with it fitting within the cowl. just not sure I want a plane that big yet.