I would go with both the JC intake and shark. I got both at the same time so I can't say whether the shark injector alone will have any gains, but feed it more air and there is a difference. Is it a huge difference "no". For $800 bucks its worth it. I can feel alot more low end torque which worked great for me in autox. It sounds great too ! If I had to do it again...well I would try mods in this order. CAI, exhaust, (shocks|springs|sways), and then Shark.