Hello, I just bought a 2003 Chevy 2500HD Duramax LB7. It came with a 6" Spectre cone air intake. Does it increase my HP or my Torque? See I didn't have a chance to drive it without the intake so I'm not sure what the increase is. Is there a bigger one that I can put on or is that big enough? It also came straight piped, is there something that I can put on in place of the muffler and still have the same sound with more power? Thx for reading...