I have a couple StALKER 51 ENGINES. They make plenty of power on planes such as LEGACY, and my own "TIBURON", (LEGACY variant) which captured a 1st place at the recent Fall Follies in Salem, OR.
Cubic inches doesn't always mean more stunting power. I have discovered that "big bore" usually means more fuel consumption without a corresponding increase in power, where it counts.
Floyd