i have been looking into getting some headers for the TBSS and have seen alot of claims of 40hp for full exhaust systems, including headers and true duals. i have always wondered if its okay to add these up when your trying to estimate your horsepower, like my cold air intake was supposedly a 18.something gain, and the e-fans and tune was around 30 and the full exhaust is supposed to be 40. i have read that components work better when together so i should get even more than what they add by themselves. but individually that 88hp on a engine making about 320whp stock thats around 400 at the wheels. not too shabby.