Prop testing

[DC18]

Well, finally got the time to test three props I have. Started with Mirage Plus # 48-13704 23P and experienced some vibration at 1500 RPM. Wasn't sure if it was the drive or the prop. We changer the prop and the vibration was gone. The second prop we tried was a Quick Silver # QS5074X, 13- 3/4 X 23P. GPS speed was 61.1 at 5400 RPM. I think that prop is too small, RPM too high. The third prop we tried was a Merc Cleaver, labbed # 48-88450, 14-1/4 x 23P. GPS speed was 67.7 at 5400 RPM. The boat definately picked up top end and the ride was smothe. I am considering a 25P but not sure if I will use a three or four blade. I have heard that the newer four blades are awseome and give all arround good performance.
Boat info is 18 Classic, 350 Mag (stock) Bravo One Drive with 1.65 gear ratio. Big Griz your imput please and anybody else also.