SERVICE INFORMATION The specifications for the intake and exhaust valves and valve lifter service parts have been changed. * The valve stem length of both intake and exhaust valve has been increased (Figure 1) and are a direct replacement for the shorter style valve. * The related valve lifter cup has been shortened (Figure 2) and the point at which the valve lifter contacts the valve stem has been shortened (not shown). These service parts will require that the valve and valve lifter be replaced at the same time. See this bulletin for further details.