To trim tab, or not to trim tab?

I have tried everything I can think of to keep my Wildcat from porposing at speeds over 40 m.p.h.. Redistrubiting weight, propellers, contemplating a belly tank, a cooler full of beer in the bow, 10 gallons of gas in the tank, ect... So now I made a hinged stainless, stationary trim tab, with 2 nice stainless turnbuckles. I have it planned to mount in the center, flush with the bottom of the hull. But, here's the big BUT! I cringe at the thought of drilling through the hull below the waterline. Does any body have any input? I modeled mine after a 1995 Malibu, so I guess the concept works.