just for clarification the zetec is not an interference engine, just be wary that as the engine gets more mileage on it, carbon can build up on the bottom of the valves and top of the piston and can cause interference. but it is highly unlikely. the timing belt is pretty easy to do on the zetecs and i have read a lot talk about the waterpump. the waterpump is NOT driven by the timing belt. the only dilema the timing belt presents is it covers one waterpump bolt when t/b is installed/has tension on it. if you have the money and want to go ahead, ok. but if money is not plentiful and you stay current on cooling system flushes/exchanges, then i have seen those waterpumps last over 150,000 miles. your call, just be advised it is not run by the timing belt.