RE: Scat Cat engine replacement?
The Scat Cat was designed around that engine (K & B .40), which is why the nose is as long as it is. The engine is very light.
I've heard good things about the Thunder Tiger Pro .36, which is also a very light engine, and based on my experience with the Thunder Tiger Pro .40 I would certainly give it a shot.
Just another .02 ...
Duane Gall
RCPRO