Which box is better for my car? sealed or ported?

Hello I have a 1994 Chevy Caprice. It has a large trunk.. I am going to get two Kicker CVR 15's and a Hifonics 1500 watt class D amp. Which box will sound better for my car? a Sealed enclosure or one that's ported with the long vertical vent on the front of the box.??? Thanks and any reason as to why the one you chose would sound the best?