This is a must for any Legend cars  power by an air cooled motor. Most people monitor their oil temperature on these types of vehicles, but there is a big problem with just monitoring the oil temperature. The temperature in the oil changes too slowly, and by the time you see the temperature rise to a dangerous level it's too late, the damage to the head, head gasket and/or cylinder walls is already been done. We found over the years that if you monitor the temperature of the number three cylinder, that is the third cylinder back from the first of the car and maintain a cylinder head temperature of under 400° your head gasket longevity will, in most cases, at lest double. We have traced the numerous problems these motors have to the excessive heat that builds up in from inadequate air movement over the motor. If you have a moment, please take a look at our cool hat, which has been quite successful at controlling many of these issues.