Tommy,

I believe if I were you I'd put in the YS... I am also a huge YS fan and for the weight, you can't touch the power... I have seen a Super Kaos with retract powered by a YS.45 and it had almost unlimited vertical. The Kwik Fli is a bit smaller than that... I bet you would be happy and any tip clearance problems would go away... but.. Don't be afraid to throw on a 3 bladed prop.. that's what they were designed for and you will see some of the top FAI pilots flying as much as a 4 bladed prop just for braking effect going down... just a thought for you.. great plane to bring back to life..

good luck,
Dan

Carolina Custom Aircraft