Bob is right about this little Bcat. Even as well built as it is I seriously doubt it can handle real high speeds. I just found the forward blind nut mount that holds the boom to the wing, loose, and it fell out with a little wiggling. You can imagine what would happen if that failed in flight. Also by cutting the wing up and mounting retracts it's very easy to degrade the integretity of the wing. A person should strenghtin any area that he cuts up.
Frankly I think l a P-60 or similar is way to much. I realize it can be derated but the extra weight would still add extra G's going the same speeds as a smaller lighter turbine.

Anyway - FWIW
Galen