how often should u change the timing belt on this car?

Your Lincoln doesn't have a timing belt. The engine runs a timing chain which should last the life of the engine. You should only replace the water pump if its noisy, faulty, or leaking.

that sounds about right and the water pump does have about the same life spand of the timing belt

This car with the 4.6l V-8 has a timing chain. You need to replace it only if it fails or during major engine work. Replace water pump also when it fails. Zee