I have a 2003 trailblazer lt, not ext, and I was thinking about runnning 2 18 xcons. Not a lot of people are running 18s in trailblazers because of the limited room in there. Crazycricket12 on smd forum gave me dimensions of his box. It's 21h x 45w x 30d. He's using the torres box calculator. The box has a square port in the middle of the box facing back hatch. The dimensions for the port is 10h x 10w x 12L. It says port area is 100 ft2 with tuning at 32.75hz. The total net volume only excluding bracing is 12.41ft3. Would this work??