In my opinion, way too much thought goes in to sealed boxes. Just take the port out, and make it fit where you want it to.

People make a big deal out of calculated response...10hz lower F3, tight bass, low bass, booming bass, etc. In reality, between reflection, cabin gain, and phase issues, it is difficult to really effect the audible performance of a sub in a sealed box.

Unless you are just way out of alignment (.25 cu for a 15, or something) it will most likely be just fine.

Toby