A good Reminder!

For a complete run down of the TSB, see the link. Compliments of Cheezit:

Ford Truck Enthusiasts Forums - View Single Post - Public Service Announcement

Was re-reading the TSB and I know several of us have readers that can monitor coolant, eng oil temp and ECT's. If you pay attention to this paragraph, you may have an idea as to your own thermostats:

With EOT at 195 °F (91 °C) drive on the highway unloaded at 55-70 MPH (89-113 Km/h) constant speed to observe EOT and ECT temp.
Test results/next steps:
If EOT is less than 8 °F (4.4 °C) higher than ECT, and the coolant temp fluctuates roughly 5 °F (2.7 °C) - the thermostats are okay and do not need to be replaced. Replace just the radiator. Refer to WSM, Section 303-03 (Engine Cooling).
If EOT exceeds ECT by greater than 8 °F (4.4 °C) or if the ECT readings fluctuate 10 to 12 °F (5.55-6.66 °C) roughly every 30 seconds - replace both thermostats and radiator. Refer to WSM, Section 303-03 (Engine Cooling).
If vehicle is not drivable and the coolant leak is found to be from the radiator, remove and replace both thermostats and radiator. Refer to WSM, Section 303-03 for both radiator and thermostat removal procedure and approved cooling system draining, filling and bleeding procedures.