1 pint of Motorcraft VC-8 diesel coolant additive for 7.3L, 6.0L, and 6.4L Powerstroke engines.
Suggested use by Ford:
7.3L: With green coolant add the additive every 15,000 miles
6.0L: Test the quality of the coolant every 15,000 miles and add additive as needed.
6.4L: Test the quality of the coolant every 20,000 miles and add additive as needed.