Devas8or

Need some input for a Dc Audio Level 6 18" enclosure, Dc audio recommends 5.5 and the slot port size from the info I have gathered is 12-16 cubic inches per every cubic foot of the enclosure so somewhere between 66-88, I Want to compete in Daytona SBN ibdl truck class 3, I have the amplifiers and the electrical getting ready to purchase the subs, any ideas are welcome, Thx.