Drop Shackle Set lowers the rear of your truck 1" or 2". This is the simplest way to lower the rear and is an easy way to make your truck look more level. Drop Spring Hanger Set replaces the original front hangers and drops the rear of your truck an additional 2". Combined with the Drop Shackle Set, you can drop the truck a total of 3" to 4". If you are dropping the rear 4" or more then you need shorter rear drop shocks.