Plan on getting headers, but I have put it off because I dont want to have smoke fumes coming into the car.do anyone have this problem? Also plan on getting Pacesetters and a catted Ypipe from Thunder Racing. What all will I need to complete the install? What will I see in horsepower gains at the rear wheels? The car is A 99 TA with hooker muffler,Lid,K&N filter, and all of the free mods.