Home About DOHC V-8 SOHC V-8 DOHC V-6 Coyote 3V Mustang 05-06 3V Mustang 07-10 EcoBoost V-6 F-150 Expedition V-6 GT350 GT500 Cross Reference Thermostat Basics Coolant Filling Installation Motorcraft Coolant Purchase
I actually did not make a "T-4" part of my line for the 2007-2014 GT500 with  the 5.4 & 5.8 DOHC V-8, but have the perfect alternative that can be found  for right around $10. This thermostat is made by MotoRad, under their part  number 354-180, and can easily be acquired through an internet search. It is  also recommended by a well-known tuner, and most likely sold by shops that  deal with the Shelby. If you happen to have an O'Reilly Auto Parts near you, they sell it as their  Murray Plus 4138. It is still the same MotoRad part, just in their box. My local  store actually has it for $12, and once you add the o-ring, it is a great deal!  The only catch here is that this is a 180° thermostat. it will, however, still  make a nice difference over the stock 192° version (Motorcraft RT-1185),  especially with a good tune and proper fan settings. If you want to save  yourself some cash, this is a great way to go about it. Although it may not  look the same as the Ford part (or Stant 49312), it is dimensionally identical  and will function exactly as needed to drop your temperatures!