Depends on which gt you are talking about. A foxbody gt can weigh as low as 3000 lbs where as a 2010 gt can weigh as much as 4500 lbs.
2997#
3000 lbs.
You would have to refine your answer because they weigh different by years and model and trim level.
The 2008 Ford Mustang GT has 300HP
The 2005 - 2009 Mustang GT has 300HP.
The 2008 Ford Mustang GT has 300HP
The 2005 Ford Mustang GT has 300HP
The 2008 Ford Mustang GT has 300HP
The 2006 Ford Mustang GT has a curb weight of approximately 3,500 pounds (1,588 kg). This weight can vary slightly depending on optional features and equipment. The GT model is equipped with a V8 engine, contributing to its overall weight.
The 1996 Ford Mustang GT was rated at 215 horsepower
The 2005 Ford Mustang GT has 300HP
Ford rated the 1993 Mustang GT at 205 horsepower