I'm building a Kavalier at the moment and will either put my OS .46AX in it or upgrade to a Saito .56. I have a build thread going in this forum, a few mods are needed to fit the Saito in the cowl, not sure how the evo .61 compares in size but you may have trouble if you go ahead with it. I'd agree though that it will be too much for this plane.