The 1970 Buick GS455 Stage 1 was no slower than any contemporary muscle car. But few people knew that fact at the time.

Buick’s top performance car was still kind of a sleeper – not much flashier than regular Skylar models. And that wasn’t helping sell a lot of cars. Any car dealer knows that you can sell more cars that look like they go fast than cars that actually do. Just look at the sport trim packages being sold today.

In order to boost its sales, Buick created the 1970 GSX special edition – Gran Sport Experimental. Now, this is the Buick muscle car that will be remembered for all time. It was bold, brightly colored with racing stripes and a big wing (for its time).

Finally, the GSX looked as fast as it actually drove.

The GSX came only as a hardtop coupe with two color schemes – Saturn Yellow and Apollo White. A tapered black stripe with thin red contour would begin behind the headlights, travel the length of the car, and wrap around the rear wing.

The wing itself was a fiberglass, pedestal-type spoiler, mounted to the back of the trunk. The side flaps remained flush with the rear quarter panel. In fact, thanks to the black stripe, it often appeared as if they were firmly attached.

The hood was painted mostly black with a stylized, central stripe of the respective primary color. Apart from the functional air scoops, a new hood-mounted tachometer was added. A satin black air dam was installed underneath the front bumper.

Yes, they put not one, but two spoilers on a Buick – and it was awesome.

The power sports rear-view mirrors came standard featuring a streamlined shape and were easily adjustable via remote inside the cabin.

The interior was fully blacked out and still as luxurious as any other Buick of its time with high-quality vinyl seats, special padded steering wheel, sound deadening, nice carpet, and other goodies. Comfort and luxury options included power seats, power windows, power door locks, tilting steering column, AC, AM radio, cruise control, speed alerts, and whatnot.

The only engine available in the GSX was the 455 V8 with 350 horsepower in base form or 360 horsepower with the Stage 1 package.

The standard transmission was a close-ratio, 4-speed Muncie unit with Hurst linkage and shifter. A 3:42:1 positraction rear end took the power to Rallye 15×7-inch wheels, wrapped in G60 Goodyear Polyglass tires with white raised lettering.

Every GSX was a fully-specced street performer – no compromise.  Standard equipment included power brakes – front disc / rear drum; heavy-duty suspension, including stiffer springs – 450 lbs/in front and 144 lbs/in rear; stiffer shocks and sway bars – 1-inch front / 0.875-inch rear.

Despite its 3,874 lbs dry weight, GSX offered the same break-neck acceleration as the regular GS455 Stage 1 – 5.8 seconds to 60 mph and 13.38 seconds to the quarter-mile at 105.5 mph, according to Motor Trend.

It’s worth mentioning that Buick was very clever with their naming too.

In 1969, Apollo 11 put men on the moon, so especially in America, everything related to experimental space flight, Apolo, or the cosmos was instantly popular. Stage 1 was the biggest and most powerful stage of the Saturn V rocket, which did the heavy lifting and Stage 2 took the spacecraft into orbit.

The 1970 GSX is Buick’s contribution to the list of legendary muscle cars – instantly recognizable on the street and at the dealership’s lot. This was the car that brought customers into the dealership, though they rarely left with one. Just 678 GSX models were produced that year.

In 1971, GM began slashing down performance in light of the upcoming emissions and safety regulations, as well as rising insurance. Even though the 455 engine was still available, it lost power as GM reduced compression ratios across the board.

Marketing took a further hit, as horsepower ratings switched to net, rather than gross. With only 260 horsepower advertised, just 124 GSX units were produced in 1971 and another 44 the following year.

In 1973, Buick replaced the Skylark model with the newly revived Century – again riding on the A-body platform. The Gran Sport reverted to a trim level for the Century and Buick’s legendary GS cars were laid to rest.

Buick buried their performance aspirations for the next decade in preparation for the looming changes in the automotive industry.

However, Buick would rise again to take the performance scene by storm in the mid-80s – this time with a state of the art turbocharged V6 engine.

You can read that story here – The Story of the 1980s Quickest Muscle Cars.

You are reading part 4/4 of The Story of The Luxury Muscle Car. Other articles in this series are available below:

1. The Story of The Luxury Muscle Car – Buick Gran Sport
2. 1697 Buick GS400 – Getting Serious About Performance
3. 1970 Buick GS455 Stage I – Faster Than a Hemi?
4. 1970 GSX – The Buick that Made Legends