The six hundred is for the ring which attaches to the stock crank pulley with set screws. Several people have had problems with this ring coming off. The Kleemann alloy pulley is $899. ASP Racing modifies stock pulleys by machining the belt plane then pressing on a ring and welding it. The modified pulley is then dynamically balanced. They sell for about $650, if they provide the stock pulley or about $250 if you send them your pulley. There are several other similar modified factory pulleys available but they are much more expensive.
A forum community dedicated to Mercedes-Benz owners and enthusiasts. Come join the discussion about performance, classifieds, troubleshooting, maintenance, and more for all Mercedes-Benz and AMG models!