Hi!
Sorry! But too big engines like the OS FX .40 or FX .46 is going to make your DC-3 fly like a pattern airplane. The problem is weight! Low weight means you can fly it like a sailplane, slow and predictable at 1/4 throttle, without worrying about it stalling. High weight means you must fly it on power ...not on it's wing...at scale speed...making slow speed flying not as joyful. Throttle management is something which is very important when flying a scale airplane ...but having too big engines is not making scale speed flying possible or as enjoyable as the airplane tends to fly faster and have higher stalling speed.
Choosing too powerfull engines always seems to be an aspect of this hobby.