box design good?

[realmofexcursion 0]

ok. i think i might have the box ready to go with all the deminsions. i play on putting 2 sundown nightshade 18s in my truck. i was told it need 12^2-16^2 inches of port area. so the box i came up with is 11.5 cubes, with a a port that is 33 inches tall and 5.5 inches wide, this will give me 181.5^2 inches of port area and i need 184 with the box size. its going to be tuned to 30hz. will this work out to be a good box? or do i need to do something different, just let me know