If Bob M told you that motor will pull to 5600 RPM,you need to prop it to turn 5400 to 5600 rpm.
If you are only turning it 4700 rpm ,its a good chance you may be detonating and losing power.
It would be faster with 1:50 gears and a 25 or 26" pitch prop instead of the 21 or 22 pitch with 1:35 gears.

Got a chance to run the boat this weekend with the 22p. The 22p is a 4blade power tech prop. The boat only ran 68.4 at 4900 rpm. I put the 23 mirage plus back on and it ran 72.5 at 4950 and might would have run quicker but I ran out room where I was testing at. It looks like I am looking to get a 23 Mirage plus and then get it labbed, as the one I am using I borrowed from a buddy. Both props show a 9% slip which I think is pretty good for out of the box props. I didn't see where changing the entire fuel system helped (more wasted money) but at least I can add more power without having to worry about fuel issues. I did play with the fuel pressure and with the fuel pressure at 7.5 and the 23 Mirage it would run 69.5 when I put it back at 7 lbs it ran 72.5 all this on 64 degree cool day.

23" Mirage +
 

I have a LH 23" Mirage plus if interested. Real nice shape. It does use Hub kit, not solid hub.

Thanks Fastech for the offer but my boat does not like LH props. I tried one and it listed terrible while underway. If it was a RH I would be all over it.
Thanks