Rocker Arm for Valve OEM Refurbished 240Z 260Z 280Z 280ZX 510Reground OEM Genuine Nissan rocker arm for Datsun L series engines 240Z, 260Z, 280Z, 280ZX, 510. This rocker arm is an OEM Nissan rocker that has been custom ground on the valve and cam surface. These rockers are sold on an exchange (core) basis only. Place the order for however many rocker arms you want and then ship to us the same number of your old rocker arms for exchange. Once we receive your core we will then ship out. We will not ship out the