I'm looking to get some answers so I come to you guys. Hoping some of you already did a few modifications and could weigh in on this. This past weekend I installed the flowmaster 40 series axleback mufflers the guy at the shop said i should get a 7 percent increase in horsepower. I have read on flowmasters site you should get some increase but I hear other people say no only helps with gas miliage. Also, i just purchased the rousch cold air intake without the tune did not want to mess with my computer system just yet. Will i get anything out of this or just improve gas and looks? If any of you can shed some light on this thanks.