The rare and unusual Buick, the 1987 GNX, 13.43 in the 1/4 from the factory. Wow.
A Gnx delivered 275 bhp and a whooping 360 lb-ft.
It also received a special rear axle housing cover made of aluminum (with GNX embossed on it) that serves as an additional strengthening element and point for the torque bar. For even more strengthening, the car body received special structural reinforcements in the form of "behind the back seat bracing" and special chassis (steel cross member between the chassis rails) bracing.
The GNX was the only Regal to ever receive 16 inch wheels. The wheels were made of a lightweight alloy and the rear wheels were wider than the front. The GNX came with P245/50VR16 tires in front and P255/50VR16 tires in the rear.
Inside, the dash had a special Steward Warner analog gauge package.
All GNXs received a special numbered plaque mounted on the passenger side dash which identified the number of that particular car (1-547).
But all of this came at a price. The cost of the GNX option was a whopping $10,995, which resulted in a final MSRP of $29,900.
Even more rare are the Buick Regal T-Type "Special T." These models had a Grand National exterior, but a Regal T-Type interior.
Production: Grand Nationals: 20,193
GNX: 547
Engines: Grand National: 3.8L V6 Turbo 245 bhp @ 4400 rpm, 355 ft-lb @ 2000 rpm.
GNX: 3.8L V6 Turbo 276 bhp @ 4400 rpm, 360 ft-lb @ 3000 rpm.
Performance:
Grand National: 1/4 mile in 14.23 seconds @ 98 mph.
GNX: 1/4 mile in 13.43 seconds @ 103 mph.
http://www.musclecarclub.com/musclecars/buick-grandnational/buick-grandnational.shtml