Asmund I mounted mine the same for the same reasons. I started with a OS70 and quickly found I needed more power. This plane is heavy, I would'nt be scared to put a 91 4c on it.I ended up putting a Saito 82. Tower 75 would be another good option. Plane flies good, mine wing rocks some but doesnt fly like its ~6+ lbs. Two things I dont like; 1. It will not knife edge, at least with a 3D props. 2. The plane is hard to tell if your inverted or upright.

I really like the way the H46 is covered but it is hard to see. I did a Texas flag on the bottom of both wings to tell inverted from upright
What engine are you using?