hey simmo, i got 306kw @ wheels,as my daily driver, i use the OS giken twin plate, it is a little jumpy but it grips so good. i recomend it to anyone that is looking to buy a clutch. as for your box mine is standard with modified syncros seems to be handeling it veryvery well,. a good os giken clutch that will hold your power would cost about $2300 + pull to push conversion, about 500 bucks.