6.4L Ford Power Stroke Harland Sharp Adjustable Roller Rockers6. 4L Ford Power Stroke Harland Sharp Adjustable Roller Rockers Product Code: RCD 6. 4Harland If you are tired of breaking rocker arms or bending push rods this is your solution. We run these same parts in our 1500+ HP, 5500RPM hot street class pull truck. After numerous broken components and rocker arms falling off this is has been our salvation. We worked closely with Harland Sharp to perfect these parts and know that you will receive the finest