Anyone know where I can find specs for a ported box for my 2 "12 kicker cvr's in my chevy silverado? Right now I have this guy that says he can build a better box then I bought, and make it bigger possibly if I prop my seat up more. I guess the box is holding my subs back from hitting harder and I want to have my friend build a nice box.. he made a box for his gf's silverado and it looks pretty tight but I wanted to see if anyone had any specs to share or know where I can find some?