The 1970 Buick GSX was a little know muscle car that was the fastest American tested by Motor Tend. It's 510 ft lb of torque was the highest American output until the 2003 Dodge Viper.

1. Fastest Muscle car of the 1970’s - Buick GSX?
Paul Katsus calls the Buick GSX the pinnacle car of the muscle car era of the sixties and
seventies. Buick is not usually the first car brand that comes to mind when naming muscle cars.
But, in 1970 a Motor Trend road test of the Buick GSX produced some astonishing numbers.
The GSX laid down some performance like 0-60 mph in 5.5 seconds and a quarter mile time of
13.38 seconds at 105.5 mph. Motor Trend would go on to state the 455 GS Stage 1 is "the
quickest American production car we've ever tested." The 1970 GSX customer was limited to
two colors "Apollo White" or "Saturn Yellow." Both came with wide black stripes down the
hood and smaller black stripes down the side. On the hood came a tachometer from the Pontiac
parts bin.
Power was from a 455 cubic inch engine officially rated by the factory at 360 horsepower. But, it
has been generally acknowledged that like many high output engines of the era, it was unrated
for insurance purposes. The 455 engine had a weight advantage of 150 pounds over other
General Motors large block mills, which of course helped with faster acceration. The 455 has
been estimated to have a true output closer to 400 and perhaps up to 425 horsepower, with the
$199 Stage 1 option. Torque outputs were not under the same penalties as horsepower numbers
from insurance companies. so were more accurate. Good thing for the GSX, which produced the
highest torque output engine at the time. In fact, the torque output of 510 lb-ft at 2,800 rpm was
not surpassed by an American car company until the 2003 Dodge Viper. For those that follow
muscle cars, that is more torque than the legendary Hemi Cuda or 1970 LS6 Chevelle!
The GSX came standard with a load of performance goodies. They included higher lift camshaft,
bigger valves, (Stage 1 option had a slightly higher compression rate than the “standard” 455), a
Positrac differential, beefier springs and a revised jetting for the carburetor. Even the
transmissions (both stick and auto) were improved.

2. The GSX was released late in 1970, so consequentially not many were built that year. There
were 278 standard GSX’s built, add to that number, 400 Stage 1 Performance Packs models and
you have a very limited production model. In 1971 there were only 124 examples made and in
1972 a minuscule 44 units were produced. These Buick GXS big block muscle cars are very
collectable, with matching numbers cars fetching over $200,000 at auctions. The GSX was both
a luxury car and mighty high performance car that is often forgotten when people recall the
pinnacles of hi-performance standards of the golden days of American muscle cars. Paul Katsus
is glad to share his love and knowledge of cars to his readers and hopes this article informs
followers of these cars.