How well is the plane built? If it can stand the added vibrations etc. created by the larger than normal engines, you will probably be okay. Just remember that the entire plane will experience higher than designed type stresses. This includes the stabalizer, fin, rudder, elevator and wing and landing gear (especially how the gear is mounted). Excess power can cause any one of these to fail if overstressed. Personally, I like the overpowered planes but they often demand judiciouse use of throttle and more than normal care on maintenace and preflight checks.