Paul, good to hear from you and thanks your comments.

I purchased the 75" WW with the intention that it would be a great fit with a high compression big bore kit in the future.
Yes, near sea level where I do most of my flying, I lost some cruise speed and the fuel burn went up at the same RPM's that I flew the 70" warp.
I also gained 20 percent more thrust at the same full throttle static rpm which is very noticeable seat of the pants.
Plus the WW is more interesting to look at.
It is hard to justify a big bore kit when this Model 4 performs as well as it does.
Since most of my flying consists of finding new gravel bars, cruise speed and fuel burn are not an issue.
The Kitfox has been a great way to live out my dreams of owning a Super Cub at a reduced cost.
Herman