Why do I get the feeling that some folks are looking a little more into this than necessary? Many auto mags that do these "shootouts" often bump the timing, put on sticky tires or play with tire pressure, do several launches to figure out the best technique with each car, and so forth. Eventually, they nail down some decent times with their "hot shoe" driver. Heck, you can take a full weight, 5 speed, '89GT with a stock 190rwhp engine, tune it, and get into the low 14s, high 13s with excellent driving technique and powershifting.
This was 2 pre-production GTs, stock, untuned, questionable driving techniques, and so forth. There were several hundred people who witnessed the hits. Sorry to disappoint. Mid-high 14s. Big deal. So you mod them like any other Mustang. Steeda, Paul's High Performance, and others already have parts on their shelves waiting for buyers.