how many cubic feet is this, and using 2 inch pvc pipe, using 4 ports how long into the box do these ports need to be, also does it affect it if the port sticks out the top a few inches or does it have to cut right off at the top of the box? thanks
4.29 cf trevor was wrong he did external measurements are these the same ports you wanted to use before? if so what is the useable inner diameter of the port?