I did the CAI & tune in my 09 1st, & felt a huge difference. Then I did the pulley & felt the same difference all over again.
Also did FRPP M-5300-L springs. Perfect stance w/19" wheels IMO.
2009 GT500 - Black, stripe delete, HID's, Shaker 1K, GT500 PTP. Brenspeed Stage 2 power package (JLT CAI, Metco 2.6" pulley, NGK plugs, & tune), Barton shifter, FRPP Stinger mufflers, 2010 GT500 wheels, Nitto NT-05R tires on rear, Perfect Flash sequentials, various chrome underhood goodies.