i have an 88 gt and was looking to lower. i just got a set of 18" wheels and was wondering how low i could go without rubbing the tires and also what you would recommend to lower it with. not trying to get better handling, just a lower stance.

You cannont determine this information over the Internet. I would lower it as much as you want, up to 1.5 inches. And if it rubs in the front, just install Steering Rack limiters.

http://www.stangsuspension.com/store/comersus_viewitem.asp?idproduct=1333

These install on the ends of your steering rack, and keep tires from rubbing...

Sincerely,