There are quite a few differences between a regular 01 GT and an 01 Bullitt.
I copied this directly from this link (follow the link to see photos): MustangSpecs.com > Specialty Models > 2001 Bullitt Mustang
In 2000, Ford introduced the Bullitt concept car, spawning back memories of arguably one of the most exciting car chase scenes in history. This took place when Lt. Frank Bullitt, played by Steve McQueen, chased down the bad guys in a '68 Charger R/T in his own Highland Green '68 GT390.
The concept was thought to be only for promotional use, our simply as a tribute to the GT390, but the Bullitt went into production in 2001, as Ford hoped to capitalize on the ever growing cult classic movie, "Bullitt." Pictured at the left is a replica of the '68 fastback McQueen went roaring through the streets of San Francisco with along with the 2001 Bullitt Mustang.
The Bullitt Mustang was meant to visually connect the viewer to Steve McQueen's ride of choice. It is a heavily modified 2001 GT, exterior modifications including: unique side scoops, 17-inch Bullitt style aluminum wheels along with lowered suspension. A unique look is given off by the C-pillars and quarter panel molding as the car seems to hug the road below. A bold brushed-aluminum fuel filler door is placed on the quarter panel. Along with a Bullitt badge and polished exhaust tips, the 2001 Bullitt Mustang definitely has its own look.
Powering the Bullitt is a 4.6L SOHC V8, modified to increase airflow. The Bullitt engine produces at least 270 horsepower, and shoves out much more torque than the standard GT Mustang. Modifications to the engine include twin 57 mm bore throttle body, cast aluminum intake manifold, high flow mufflers for increased power and an aggressive sound and an optimized alternator along with pump pulley ratios.
Bullitt's modified suspension creates a firm ride. The car is lowered 3/4 of an inch (1.9 cm) for a firmer, better balanced, ride along with improved handling capabilities. This performance-handling package also includes re-valved Tokico struts and shocks, unique stabilizer bar placed in both the front and rear of the car, and frame rail connectors. Excellent braking capabilities is generated from the 13-inch Brembo front rotors and performance callipers.
Found in the inside are performance bucket seats with Dark Charcoal leather trim. A brushed aluminum shifter knob, shifter bezel, and door sill plates are also very evident features. To finish off the performance design are aluminum pedal covers. The instrument cluster is a modern interpretation of the 1960s design found in the GT390, designed to offer unique curved numeric speedometer graphics and a white-lit background.
The 2001 Bullitt was offered in two other colors than the Dark Highland Green that Frank Bullitt chose. Also offered was the newly introduced true blue, as well as black. Total production for the Bullitt Mustang was 5,582, consisting of 723 true blue Bullitts, 1,818 black, and 3,041 dark highland greens.
I have quite a few friends who own Bullitts so let me know what else you'd like to know about them.
My friend Michael owns this baddass Bullitt that was featured in 5.0 Mustang and Superfords mag as well as Muscle Mustangs and Fast Fords
2001 Ford Mustang Bullitt - Mustang 50 Magazine
2001 Bullitt Mustang - Muscle Mustangs & Fast Fords