Aftermarket thermostat kit,direct replacement Package includes thermostat,18-7170 o-ring & gasket 18-0398 Replace part number:18-3554 3852216 383307 9-43028 Application specific design to ensure a perfect fit Temperature Rating: 160°F/71°C Fits OMC 350 hp 1989-1989 350hp 4 stroke 5.7 liters 8 cylinders; 4.3 liter 1987-1993 4 stroke 4.3 liters 6 cylinders; 5.7 liter 1987-1989 4 stroke 5.7 liters 8 cylinders; 5.8 liter 1989-1993 4 stroke 5.8 liters 8 cylinders; 5 liter 1987-1993 4 stroke 5 liters 8 cylinders; 7.5 liter 1987-1989 4 stroke 7.5 liters 8 cylinders