I was just wondering what you thought was the best 400EX pipe and silencer? I kinda like the stroker because not many people around here have one. Is this a good one or should I go with some other.

 

never herd of it as long as it has the over size header pipes it will be ok. the slip on silincers are not as important as the headers on the 400ex,rapter, or ds660. the stock are just to restrictive.

 

The stock head pipes flow fine for a stock 400ex.
There is no need to get bigger ones unless you do some motor work or at least a cdi box.

 

Personally I wouldn't do anything with the exhaust unless you plan on doing motor work. The $200 you are going to spend on a exhaust will not make that much of a difference in power. It will be louder that stock. I put a WB R4 on my 400 and noticed nothing except the loudness. If you want to do something to make your 400 faster, spend the $200 on a higher compression piston and a 416 bore job.