Muscle Cars
1970 Buick GSX
Buick's baddest boulevard bruiser arrived in Saturn Yellow fury, packing 510 lb-ft the factory quietly understated.
Hero: nakhon100 / CC BY 2.0 · Wikimedia Commons
Buick's baddest boulevard bruiser arrived in Saturn Yellow fury, packing 510 lb-ft the factory quietly understated.
The 1970 Buick GSX was a limited appearance-and-performance package on the Gran Sport, offered only in Saturn Yellow or Apollo White. Its Stage 1 455 V8 was rated 360 hp and a class-leading 510 lb-ft of torque — figures widely regarded as conservative.
Buick entered the 1970 muscle wars quietly but devastatingly. The GSX package — on the Gran Sport hardtop — added blacked-out striping, a rear spoiler, front air dam and hood tach. Only 678 were built in a March-May window, split between Apollo White and the iconic Saturn Yellow.
The optional Stage 1, on roughly 400 of them, added bigger-valve heads, a hotter cam and a tuned Quadrajet. The conservative 360 hp rating likely masked closer to 400 — a tactic to sidestep GM's power-to-weight insurance limits. Motor Trend ran a 13.38 quarter at 105.5 mph.
Despite the performance, the GSX flew under the radar versus the GTO and Chevelle SS — which only added to its mystique. Proper production ended after one model year (1971-72 totaled just 168 combined). Today the Stage 1 GSX is among the most underrated muscle cars of the era.
The numbers that matter, each cited to its source. Where a figure is disputed or unconfirmed we hedge or leave it out — never guessed.
Factory rating widely held understated (~400 hp est). Motor Trend: 13.38 sec quarter @ 105.5 mph.
Standard engine on GSX without Stage 1.
| Year | Trim | Body | Built |
|---|---|---|---|
| 1970 | GSX Stage 1 | 2-door hardtop | 400 |
| 1970 | GSX (standard 455) | 2-door hardtop | 278 |
~400 Stage 1 of 678 total GSX (Mar-May 1970); some sources cite 488 of 687. Remainder of 678 total.