white brothers pro meg

[interceptorz28]

I am about to install a White brothers full exhaust on my 400ex. I think its called Pro Meg. I bought it for a real good price in anticipation of a big bore/ cam kit.
My question is: what will be the performance results installing this on my basically stock 400ex? I have a 42 pilot jet installedwith stock main and many other main jets sitting around to test it with.

Is this going to be a waste of time until I get some engine work done or will it be good?

[†2005 400ex†]

no not a waste of time, you just wont use the full potential of the exhaust untill you upgrade the motor