I was wondering if there was any power advantage to aftermarket header pipes? I seen a 400ex with them and they looked the same as my stock ones, but they were chrome. They looked the same diameter and everything.

 

my power bomb header is larger in diameter than the stock pipe. when I put it on I had to remove the plastic heat shield due to the pipe being fatter than stock. I would say leave it stock until you do motor mods. After that the header will make a little difference.

 

I have motor mods. Read my signature. So it would help some? How much, 2-3 hp's?

 

I heard you don't need one till you really get in to the motor. I don't have a complete system but I am shopping. I would think with the listed mods you are getting close to needing one.

 

I've read reports of chassis dynoed 400ex's and they say changing the headers don't make a difference, maybe a little bit but not for what you pay for. if you got an extra 250.00 go for it. But your stock headers are supplying enough flow it's just the muffler holding it up. just add on a slip on silencer and your ready to roll.