I don't want to recommend having less prop clearance because more is definitely better to a point, but I want to point out a few things.
The FAR is for certificated planes so does not apply to us although it is certainly a good recommendation. I think that there are very few KR taildraggers that have 9" of clearance. I think 7 is more typical. 9" on a Citabria or Cub is not the same as 9" on a KR or other smaller plane. When you have a larger plane with the prop many feet in front of the gear you don't need to get the tail up to a very high angle before that 9" turns into zero as you do with a shorter plane with the prop not as far in front of the gear. Again, more is better, but 9" on a KR may not be a realistic goal. My prop for my Mustang 2 is at the shop now because after almost 150 hours at five and a half inches of clearance I want another inch.
