As an experiment I recently removed my gsc prop (66 3 blade)& fitted a airplast 63 3 blade. After a runup 5750 static(I know that's low but that's just how I run it ) the pitch was checked as a start point.
The airplast was fitted and set to the same pitch ,the revs were now 6400, 2 degrees more pitch saw the revs on the tiny tach 5850.
Time to fly. The tail came up straight away 5900rpm about 10 metres shorter roll similar climb .Level flight was the surprise ,egt cooler (1000) I leaned to1150 and backed off the throttle to5600rpm.
I couldn't believe my eyes 75kts ,KNZ never does that! A couple of hours flying have confirmed an approx 8kts increase in cruise speed for the same revs(I usually fly 5500rpm 1150egt for 13 lph).I will check fuel burn when weather improves
The moral of the story
Don't be afraid to experiment ,the gsc looks better but is now retired (21years old)
Any one had similar experience?