Building a tunnel tab

[Mr. Demeanor]

Going g to build a tunnel tab to help keep the bow down on hole shot. My tunnel is 34" wide and I found a 36" x 9" Bennett trim tab that would work perfect but its solid stainless and weighs 15 pounds.
I could use some advice one what thickness aluminum to use. I will bend 90's on the ends to stiffen it up and add some braces out of angle. I plan to attach it with a piano hinge and use threaded rod and Heim joints to make the angle adjustable.

The transom has a notch at each sponson so it wont be a true tunnel extender. It will only extend the top of tunnel and work at slower speeds where I need it. More of a big trim tab over the tunnel than a true tunnel tab.

This is an old pic but you can get an idea.