Anything more than 3HP will be a monster combo. A DLE 35 RA makes about 4+HP which will make it unreal I bet. The OS 160 makes about 3.5HP and its light. The plane, engine and Pitts pipe balance out, no added balast. I removed the wheel pants and use scale Robart wheels alone like the PT-17.

Watch the ground clearance if you use an 18in prop.

Id love to see that DLE 35RA in there post some video if you do!