You listed 8 cvr 12's... If I was you I'd do 6 CVR 12's. You'd be getting more power to each sub. Also used to have a durango, and I could fit a little over 12 cf with the 3rd row out. Your not going to have enough room for 8 ported. That would be less then 1.5 cf each ported. Hell they need that much sealed.