I got 04 g35 coupe automatic. I'd like to install a header. Which brand do you think is good for it? Does anyone know how much does it cost to install it? Thank you in advance.

 

It all depends on your shop, but il warn you now headers are one of the most difficult things to install on these cars, so be prepared to spend a bit to put them in. As far as best im not sure i know momentum made a nice set if you can find them, long tube headers will give you the most performance. Keep in mind you will need to tune her after you do a mod like this or testpipes, the factory headers are only like an inch and a half in diameter on the inside. My aftermarket set were 2.5inch so its a huge difference in flow.