I have an Ultimate Pitts and it's an excellent flying plane. Probably the best flying 60" bipe on the market tody, but it is not a 3D airplane. One of the few that will actuall let you make an approach with a dead engine at a reasonably slow speed.

I had an OS BGX 3500 in mine and it was well overpowered. The BGX was a bit lighter than the 42cc engine you want to use. I had a problem with balance. The plane was quite nose heavy until I moved the flight battery to the back of the wing saddle and added 2 ounces of lead to the tail. I would have preferred not to have added the lead, but there were no other options since I had built the plane without provisions for aft mounted servos. With yours and the intended engine, aft mounting the servos will be mandatory.

As an after thought, if the plane is not yet built, don't try to inprove on any of the flight surfaces. There's more than enough as designed.

Pat