i am looking at putting a supertigre 51 in an extra 300s 40size arf

anyone know is this a good engine?

Wonderful motor. You can't go wrong with it. It'll work well in a 40 size ARF.

Fantastic engines. Don't go running it in like an ABC though!!

Have one that is great, a little hard to tune initially but now hardly ever requires much more than a click one way or the other and comes out screaming every time. It's a keeper