Billet head for the Kawasaki 650 engine. All ADA Racing billet heads are made from 6061-T6 aluminum and CNC machined in-house for consistency and performance. The head shell is then anodized for durability protection against salt-water corrosion. This is the head shell only and includes orings that fit into the grooves in the head shell and brass fittings. You will need to order domes below under Related Products.