That is why I call it the "Dream O Meter". Mine was about 3MPH fast when it worked. Looks like you are on the right track with the 23 Mirage.

So it went 60.6 mph on GPS at 5200 rpms with the stock 23P prop the boat came with new in 1989. I just put a 23P Mirage Plus on it. It went 60.4 mph at 5400 rpms on GPS with the Mirage Plus. I'm sure I could get the extra .2 mph the water was a little smoother the second time but very smooth both times. Same location. It was a little warmer out the second time and more humid. This isn't what I expected? I assume the higher rpm is because the prop is lab finished? It must be slipping more to run the same speed at higher rpm though? The one thing I did notice is it seems to stay on plane easier, cruise faster at lower rpms and I can trim it much higher before the prop starts getting air. What should I try next? I was thinking a 25P Mirage Plus??? Thanks.

If you are willing to spend more $ on props, I suggest you get a prop expect to work with you. No matter what you do with props, it sounds to me that you have likely maxed out your MPH...maybe an additional 1 MPH left.

Dont waste your money on a 25p mirage plus. I have that prop on my 26' Chris Craft Limited..except my warmed up 502 Mag with 4" thru hulls is making 500 hp or close to it, and it turns that motor 4850 rpm with that prop. What I'm telling you is your not making enough hp to turn that prop, and it will no doubt pull that motor down. I think youll be lucky to turn 4500 with that prop behind your motor. Work the 23..or try a 4 blade 21p.