Eli, you should have went with a sub that performs in a sealed enclosure. It would have been a helluva lot easier. Ported boxes are a major PITA to tune, especially when you have dimensional restrications. I wouldn't stress too much over this, it probably won't be your last box for this sub. This is going to be more of a trial and error type situation...which is the case so many times in car audio unfortunatley.