PROPER ENGINE MOUNTING HEIGHT ON TRANSOM

[wetcrash3047]

My 2004 Johnson 150 Saltwater Edition is mounted on the second bolt from the top on my 2004 Sea Boss 210 center console. It appears that it could be raised up two bolt holes.
The cavitation plate is within 1" of the bottom of the boat. When in the water and while running there appears to be 3'-4" of water on top of the cavitation plate.
This boat was recently purchased and I am having trouble finding any information about it. From what I have read it is the same hull design as a Sea Pro, so I figured that I would try this forum.
I have attached a few photos which will hopefully help. The propeller size is 14.8 x 17 RH and it is aluminum.
After running the boat two times my maximum RPM's have been only 4200 with a top speed of only 35 MPH. The boat does have functioning Bennett Trim tabs.
I have been advised to raise the engine up 1 bolt hole which I understand could raise my max RPM's, increase speed MPH, and increase fuel efficiency.
Does anyone have a similar engine set-up on their 21 foot Sea Pro? If so what bolt hole is yours set on?

[T-Topless]

I don't have a 21' SeaPro, but raising the motor can help, as long as you don't bring it up to where the motor comes out of the water when running in waves.

Propper prop (no pun intended ) is very important. What diaXPitch do you have? Might need to drop down 2" on pitch.

Here is Mercury's motor height determination (XL is the eXtra Long shaft = 30") as a reference. I couldn't find the same thing for Johnson/Evinrude/OMC, but here are thir Operators Guides: www.operatorsguides.brp.com/SiteMods/OP_GUIDE/OPGUIDE_Login.aspx?ReturnUrl=%2fdefault.aspx%3fbrands%3dej%26lang%3de%26type%3dog&brands=ej&lang=e&type=og (FREE!)

[Simple Man]

You are trimming the motor up until it starts to cavitate or the boat starts to porpoise at WOT throttle right? Proper trim will make a huge difference in your WOT rpm's.