Its going into his GN. I built it this way with the specs he gave me so the subs will clear his 5 x 7s. Each 12 has a little over 2.0 cubes per woofer. I fired it up in my GNs back seat and they sounded pretty healthy .
I did use carpenters wood glue on every joint HEHE. If you want something built, I can do it with your dimensions and ship it out to you if you are interested.