Kawasaki ZX636 Superbike Package. Dano’s Performance has developed this Superbike Package for the 2013-18 Kawasaki ZX636 models. One of the great features of this package is that you only need to remove is the cylinder head to install it. The typical horsepower gain achieved with this package is 14-16 horsepower (136-138). The following is all that is included in our ZX636. 1 Cylinder head porting which maximizes intake and exhaust air flow. 2 Install new valve stem seals. 3 Resurface the cylinder head base. 4 Custom intake and exhaust cams. 5 Custom thinner Head gasket. 6 Manual cam chain tensioner for precise cam timing. 7 Three angle valve job. Cylinder head will be complete and ready to bolt back on to your engine. This product is only available to U.