Exhaust suggestion
JBA headers, stock "H" pipe, hi-flow 2 in/2 out cat, dual 2" to the muffler, Borla XR1 dual 2" in, single 2.5" out, then 2.5" to the tip, the tip is 3" and incorporates an exhaust control valve (it is supposed to maximise torque at any given engine RPM).