I just read an article in my new Car Craft magazine that showed how to install a Pro-M Optimizer into a '95 GT. Seems to me that it should be the same unit for a '93 and earlier, since they use the same style MAF connector.
To make sure, just go to the Pro-M site and see if the part number listed for the Remote Optimizer is the same for a '93 as for a '94/'95.
Here's the site:
www.pro-flow.com