Okay, I removed my old bulkhead fitting today on my tank and installed my DIT overflow boxes. I am going to try to post some pictures doing it old school so we'll see how it turns out.
This is a picture of the screen bulkhead that I am removing. There are 2 of them and I am just not getting enough water flow to the sump using these and I dont have the room on either side to add 2 more.
After removing the bulkhead, I cut out the area between the bracing to allow a space for the new overflow boxes.
Here is what the new box looks like. It's made of plywood and coated in liquid rubber. There are 2 1.5" bulkheads going out the bottom of each box into a 3" pipe that leads to the sump. A 3" pipe will enter each end of the sump. In the top view that is not exposed plywood, it's just a little sawdust.
Here is the box, well one of the boxes installed with a fresh coat of liquid rubber. I will be putting poret foam in the front of the box to prevent fish from entering it. The main body of the box will be opened for right now but it will be a nice place to put filter media in the future.