I have an 06 GT convertible. I currently have MAC mufflers. I love the deeper, throatier sound. However the drone at 1,800-2,000 RPM (Btwn 40-60 mph) is a little annoying. I am not too concerned with increasing the horsepower (although I wouldn't mind if it did), and I do not want to make my car any louder (although deeper throatier sound is always welcome). I definitely DO NOT WANT anymore drone. I am considering the following mods, and was wondering if anyone could advise me the pros and cons of each, and what the effects would be on sound, torque, and gas mileage:

1. Headers (shorty)
2. MAC Prochamber (with hi-flo cats) exhaust
3. SCT flash
4. Gears (3.73? or 4.10?)
5. Shaker Cold Air Intake by CDC

 

If you wanna get rid of the drone, the only way to go is with the corsa exhaust system, it's not cheap though