Mustang Thermostat and Mustang thermostat housing are two things you want to be working properly. Stock Mustang replacements or performance aftermarket thermostat for your 5.0L or 4.6L can make your Mustang or Cobra warm up a little faster. With brands likeFord Racing Performance Parts and genuine Motorcraft thermostats, you can't go wrong! Mustang Thermostat Housings, also called Water Necks, are notorious for pitting & oxidizing. Replace your shoddy looking or leaky Thermostat Housing Water Neck today with a brand new piece!