i dont think anyone meant harm in posting here. its easy to take things written wrong.. they saw improvement on that engine that way. i think thats very true. the point was ,,, can i get the same increase by changing the cam/port exhaust velocity ..... or other items ? its all air flow .this shows a weakness in the engines ability to get air out of the exhaust side.. i dont care how you get it done. the wrong set of headers will hurt it. this is more about -tuning- than actually making power .. simply put, just adding headers to an engine does not mean it will make more power. if the engine needs help with exhaust ,it will help and the better matched to what the engine needs the more help it will be.