No need to worry about warped factory blocks any longer...the new CC Racing Billet isolator blocks are by far the nicest on the market. The mounting bolts are enclosed in the block to strengthen and make sure the block won't bend. They are machined so that the two Teflon gaskets fit into the Isolator block on each side to make sure it has tight seal on the engine and carb. The Teflon gaskets not only keep the heat from the carb but also help to cool the incoming charge of air and fuel. When we were testing them on the dyno after three back-to-back pulls the Isolator block was ice cold. They have been anodized black to help prevent from any kind of corrosion that may occur in our marine application. They are approximately .100" thinner than the factory block to add some performance without taking away bottom end torque. It comes with all Stainless Steel bolts, washers, button head carb screws and Teflon gaskets.