A 2-bladed prop is more efficient than a 3-blade, so more engine power will be converted to thrust. But, you need to pick the correct 2 blade prop. Low pitch will result in more pull but less top end speed. Higher pitch will give you more top end speed but less pull (thrust). Pick the combination of pitch and diameter that will allow the engine to reach its top recommended RPM range but not over-rev the engine. The manual should give you acceptable combinations.

Also, an APC prop will generally get you more power from your engine than say a Master Airscrew, TopFlite, or Zinger.