1. Flowmaster catback 0
2. Long tube headers 15 to 20
3. y pipe 0
4. LS6 Intake 5 to 10
5. 80mm Throttle body 0
6. 85mm MAF sensor 0
7. Lid 5 to 10
8. 3.73 gears 0

My math says 25 to 40. Do not have a muffler shop install your headers unless you know them well. Find a shop that knows these cars or do it yourself.