SSM's technically can lower the ride height. If the rear pivot point of the LCA is moved down an inch that means that the spring purch (since attached to the LCA) will also be lower than its original position. Being its not on the end of the arm it may only lower it 3/4" or something.

SSM will also increase your AS. This means it will hit the tires harder but can unload quicker if you don't have a loose nose to keep the load all through the 60'. You also need adjustable uppers to dial in your PA. But you may want to also look at UCA's that relocate the rear pivot point. This will move your IC back and increase your AS.

Have you ever plotted your suspension?

-Mark