There is a lot of things flat out wrong in that article. I stopped reading about half way thru. Whoever wrote it either doesn't know much about trucks or was writing it for an audience that doesn't know much about trucks.
Forget the suspension block, that gains you nothing but lift. Airbags will help or just getting replacement stronger springs.
You will need to make sure you don't exceed the weight rating of your rear tires regardless of what badge is on the truck. Also, you don't want to exceed the rear axle weight rating. However, Ford often just makes the rear axle weight rating the same number as the factory tire weights. A little research should get you the actual weight capacity of the axle, not just the tire or truck rating.