I got an ACT stage 2. I think it was a little pricey and I heard some bad things about the design. But I was in a pinch and needed it asap. As far as compatability I am not sure but I think they are (b series clutches) the same. Im still trying to figure out if I can use any b series flywheel with the clutch I just bought. I will let you know if I find out though.