The prop is going to look small in front of that big round cowl... I'd start with an 11x6 myself... I think you'll need more pitch to fly the plane than your 11x5 will offer. A 12 inch prop would look better...I've never had a .46 that spun a 12x6 very well... they will turn up an APC 12x4 nicely BUT again I think that plane will need more pitch. If you really want a nice size prop hanging off the nose... go 4 stroke

John