Hi!
.46 will be way way too much power and weight.
It is vital with all airplanes that you build them light.Using large .46 two-stroke engines will only make it fly like a pattern plane and not like a scale DC-3, that is my experience from 33 years in this hobby/sport,flying both pylon racing as well as scale and sail-planes.
When I want to fly fast I race pylon racing . But in scale you have to fly on the wing! That mean building light and use the lightest equipment possible. And four stokes makes a much nicer sound when flying a scale plane.

Large engines demands larger tanks, larger motor mounts and beefier structure to hold the engines. A weigh increasing spiral.
Using smaller engines on the other hand permits the use of lighter structures, less fuel (I use tin soldered tin can tanks of 110cc) and makes the engines less visible to the eye. Vital is also to have engines that give a smooth power acceleration when you give power.
These small four strokes do just that...they give a smooth ride. .46 engines wont deliver that. The power comes more like an explosion with .46 two strokes. Not good when you fly a twin scale model.

I have engine nacelles in glass fiber and carbon fiber scale props available if you are interested.