Mxsmanic wrote:
In most cases I see somewhat lower speeds in cruise. I'm trying to
figure out what I did different this time (or what might be different
about conditions) that would produce a noticeably higher speed.


You don't say what the air temp is. But anyway, this is all
academic in terms of a simulator, but there any number of
things that can affect the airplanes actual (TRUE) airspeed:

Weight
CG (loading)
air density (temp/pressure)
power (RPM)
propeller efficiency
how slick is the fuselage/wings? (parasitic drag?)

Through various combinations of these an airplanes max
true airspeed can vary considerably from ;book/ values.