I think one of the problems I had with the 120SP's was not enough load running the 15.5" x 12" APC prop.<div>
</div><div>Having set up a 61SP in a small Sea Fury, I ran it at 4.2K rpm swinging a 15.5x12 four blade, which surprised the %^&$ out of me.</div><div>
</div><div>This prop has since been trimmed to 14" and flown, spinning at 4.8K rpm. </div><div>
</div><div>So I think the 120SP might surprise you on what it can actually spin.</div>