your get more bhp with post 06,ive read its about 2-3bhp pre06 to post 06,add the 2-3 your prob losing with your current set up so imo its worth it,ive tried loads of breakers & still no joy,ive got a spare 55reg box you can have for nowt,on ebay they are breaking a 2007 zed,the box is no good(heavy front end) but i think the pipework is ok,there number is 01616822221