Let's say one was building an airplane and needed an engine in the 65 peak hp range. The airplane would be a slow single seater with the 1835 being a candidate for an engine. Considering the tiny weight difference between the 1835 and 2180, would there be any advantage to using a 2180 propped to peak at a lower rpm that produced around 65 HP? I would assume that you would get higher torque and lower temperatures than the 1835 but that's just a guess. Also would the longer prop be more efficient and in turn actually require less HP to produce the same results?