exedy stage 2 cerametallic, it's a little easier to live with than the cc stage 4... although i think jpslick said he drove someones car with the exedy stage 2 and it was stiffer than his cc stage 4 :dontknow:. the exedy stage 2 cerametallic design is more resistant to wear from someone trying to slip the clutch due to more overall surface area to clamp. i'm sure both are just as durable as the other as far as reinforcement goes for hard engagements. the act stage 2 will blow your master cylinder fast from the increased pressure over the others. although you should probably replace your cmc with the em2 model anyway.