Air Intake, Exhaust

[H2Much]

I am looking to get a cold air intake for my ride, the tiem has come. A couple of questions to some of the techy people or those who have been there, done that: First, will installing a cold air intake really make that much of a difference in performance? I have been looking at and studying the stock intake in there now, and it seems to already draw quite a bit of air, so I wonder if an aftermarket cold air one would make much of a difference. I do have a programmer chip as well, so maybe that can help someone answer this question.

Second question: If so, what is a good cold air intake that is legit on the dyno?

Also, I posted a while back regarding information on a custom exhaust system, and I got great information. Since, then, I have had a little change of heart and am probably looking for a bolt on instead of having it done custom due to the fact there are zero experts on that stuff here where I live. Also, would doing a bolt on aftermarket exhaust system help me in performance? The overall goal I am looking at with these upgrades is to increase top end power and get better gas mileage. If these will help, let me know and what suggestions you may have.

Thanks team.