OK, here's the poop -
For the Mach 1 grill delete, the "Radiator Cover" is XR3Z-8C299-AAA. For the Cobra, it's 2R3Z-8C299-AAA. Thankfully, people like Randy Stinchcomb keep me in the know...I bought this stuff (and more) from him, via ModularDepot, Liberty Ford.