What would be the perfect size ported box and tuning frequency(hz) for a JL 12w7 to gain the most SPL I can?

I KNOW its an SQ orriented sub and not geared for SPL but I already made the quik/wrong decision and bought it so its done and over with but before I sell it I want to see if I can outbang JL's H.O. box that I bought it in so I want to build a ported box tuned to the best possibke frequency (hz) where the 12w7 will put out the most Spl it possibly can.. So I want to know how many cubic feet the box shuld be to obtain that as well as port length and width and how many Hz it will be loudest at so I can build the ported box for it before I sell it. Any info or links or emails (if easier) would be greatly appreciated Thanx so much in advance! joeg1488@yahoo.com