Engine height w/notched transom (Fountain)

After getting my Concept set up right only to have it burnes by some punk kid down the street I am starting all over again. As seems to be common, the boat is set up very safe with the engine mounted all the way down.
I bought an 04 23' Fountain (non-stepped) that has a 15" notch in the transom giving me 15" of setback. The hull has a 22.5 degree deadrise. The boat was set up with a single 225 Merc Opti mounted all the way down. Set up like this, the propshaft is 3.5" below the bottom. The motor definitely needs to come up based on my cav plate. The boat also porpoises pretty bad and I am hoping to relieve some of that. The question is how high can I come up as I would like to get it right the first time. If I come up two holes I am still 2" below which still seems low with that much setback.
I am turning a Merc Rev4 prop so I should be able to go fairly high and still hook up. I have searched all over the various forums for setup info on this particular boat without any luck. Several calls to Fountain and messages left without a return call.
Since the Optimax motor has low water pickups in the nose can I go higher without worrying about water pressure or will it be a problem if I start sucking air in from the top of the side pickups? I dont think I am in any danger of that going up two or three holes as it is.
I know this isnt a typical boat for this forum but the fishing guys dont seem to care much and I want to get the most efficienct out of her that I can.
Thanks in advance.