I think the confusion in this discussion stems from some not knowing that 7.3's used the green Ethylene Glycol Coolant and the 6.0's used the Gold Ethylene Glycol Coolant. The difference in these two coolants (besides color) is the additive package. The green coolant requires the use of an addtional additive purchased separately (Motorcraft Part # VC-8, I believe) whereas the Gold Coolant is sold as a concentrate with the additive already mixed into it. However, I'm not sure the Gold Coolant can be used in a 7.3 but that is a topic for a separate discussion.