The originals were a bad design. With holes on the bottom of the boxes, as soon as you get up on plane, the water will run right out. That's the problem cessna' had with his.
I'm changing them up a bit so water will stay in the boxes while on plane-
Installed a sealed tube inside the box with clamshells under the tube so while youre running, water continuously pumps into the boxes.
So water can run out while on plane, and flow in/out freely while at rest, I'm putting screened overflow/inflow holes right at the waterline on the boxes.
Now I have no holes in the bottom of the box to drain them. I'm thinking of using a S/S pipe plug and tapping them into the bottom of the boxes. Pics to come!! (I promise)