The warrior was in production 12 years before the 400ex so how did they make it to compete with it if nothing changed.? And I said stock vs stock you just repeated what I said.
Get the custom header and find a good used white bros slip on. Also open the airbox up. But I have a hard time believing that you make them look like they are standing still? A stock warrior isn't much compared to a 400ex but a modded warrior will eat a 400ex
I would get a hmf or white bros slip on and a sparkymichigan torq header pipe(do a search) if he will still make you one also get a k&n with an outerwears and take off the lid. You will get a good amount of sound with that and quite the power increase!