The Datsun "Z" cam oilers are no longer available. We started making these as a result. The blocks are CNC machinedand the oil tube has cleanly drilled holes that supply a much stronger stream of oil for the rocker arms.Original Datsun cam oilers had stamped oil holes which hurts the oil flow.Our cam oilers are used by the biggest Datsun Racing engine shops around the world because they work the best.