Hi Darren . I have an Avid mk4 with a Subaru motor in it, which is great but I need the stretched fuselage to balance it. I have added a ventral fin to stop it wagging its tail, which with lighter engines it does not do . If you didn’t know these aircraft were really only designed for a light weight engine like the 582 and when kept light have an amazing stol performance. I have owned mine now for 15 years and love it, BUT if I were to repeat it again and after seeing what the 2200 Jabiru engine does in this airframe I would install the jab engine. As a tail dragger it is a real handful as mine is set up ,I have ground looped mine only once(and believe me that was enough) with lighter engines it would be better, good luck and keep in contact