I'm running those tyres under the later PR spats on my RV-6. I read a number of threads on here before going down this route and I'm pleased I made the change. I had to enlarge the opening of course, but it was only a days work to replace the tyres, grease the bearings and trim the spats to fit. I had to move one lower anchornut on each side for the new edge clearance, but otherwise it was easy and straight forward. I have about 1" clearance from the top of the tyre to the inside of the spat.
I don't have any clearance issues on the sides like Daida, above.