We offer a lowering spring with 1.25" front and 1.5" rear drop. The springs have a lifetime warranty against spring sag and are in stock and ready for same day shipping. The D specs are a great strut/shock but i would also recommend an adjustable panhard bar, your going to need one if you lower your car. Here is a link to our site. Our prices are very competitive on these parts. If you have any questions or would like to place an order please give me a call.
http://www.bmrfabrication.com/2005Mustang.htm