the C4 does'nt come cheap , its was about $4000 with converter. It sounds like alot of money but the proof is in the box. the box is very very strong. my mate has got a dominello C4 in his VL and it made 440hp on the dyno, also ran 10.51 @128mph. You have to look at this way, get the box done right the first time. because if dont you will have to pay $4000 on top of the first rebiuld price. Trust me guys been there and done that, you will be kicking yourself in the long run if go the cheap way. you dont have to go to dominello , i'm just saying that anywhere from 3000-$4000 you get a strong box