Centax clutches! Best clutches since Hudy and Serpent in '83! The start of the 2 speed. Quattro- Vector- 700 series, to 988 models. All basically the same, Shoes change material single to 3 peice shoes. Wont hurt to even use emery cloth to shape the shoe. Hudy and Serpent the pioneer of Centex 2 speed clutches.