Is a longer prop, say with the same pitch as a shorter one, going to give you more speed because there is more blade pulling you though the air? If so, how much flatter can that long prop be than the shorter one and still keep up with the shorter one? Say you had an 86/43 and an 84/43. Would the 86 propel you faster than the shorter one with the same pitch? Then if you had an 86/40 say vs an 84/43; are they propelling you the same speed or is the 84/43 going to be faster?