How much more horsepower will you get if u add headers and coldairintake to a 2008 mustang v6?

Well you really will not gain nothing except extra gas mileage if u add the cold air intake. As far as the headers idk, It really depends what u want the car for and what are u going to use it for.

each car is different with its mods. headers for a mustang may not be as good as headers for a TL... your looking at prolly 20-30 hp (both mods) depending on your car.

20 at most

If you're not worried about gas mileage just get the GT. A V6 will never match the performance of a V8 with these mods only & won't sound half as good. Plus get Swepco oil in the engine, tranny, & rear end after 3000 miles & the car will last a long time of abuse. The engine oil will only have to be changed every 7000 miles (depending on hardcore abuse) & you'll probably never have to change the oil in the rest of the drivetrain.

Abouit 2-6 hp and 1-3 MPG as it says in K@N catolog. With free flow converter and muffler you can double that.Cold air intake is not going to help much if you are restricting ehaust flow causing back pressure that is too much for much improvement. also you do not want a fast V6 as the brakes are way too small as is suspension.

well it depends on what brand headers and cold air intake, i think