Hey Bean i am planning to run a overflow system very similar to yours except do to size restrictions and tank design i have to change a few thing and was wanting your opinion on my design. My overflow box will be attached to the back of my tank and the tank will be cut to allow water to run in, the dimensions of the overflow will be 28wide by 5deep and 5 tall and the 1" bulkheads will be through the bottom of the overflow and it will be similar to this setup
and this is the design i have so far
It is all 1" and from the bottom of the overflow to the center line of the "T" is about 3 1/4"
does this appear that it will function similar or do you think i will have problems and suggestions or opinions will be greatly appreciated Thanks