To port or not to port?

Well......Here is my problem

I have been building a box for 2 Infinity Reference 12's.....I havent checked the airspace yet but i purposly built the box bigger than i knew it had to be......So here lies the problem....

Should i:

A: Port the box (ported boxes need the extra airspace) and from what i hear hit harder....(Im a noobie so i dont know that for sure)

B: Keep it sealed and use some wood to fill up the extra airspace... There is also the problem of sealing them....On Crutchfield they have the recommended box types for these subs and they say not to seal them????WHY DO THEY NOT RECOMMEND SEALING THEM???

extra info: I am looking for a box that deals some low hard hitting base but yet i dont want it to sound like S*** Thanks for the input