1970 Buick GS455

The words “quickest muscle car ever” and “Buick” converged in 1970, when Motor Trend tested a GS455 Stage 1. The Skylark-based GS — with an automatic, a soft suspension, and comfortable seats — tore through the quarter mile in an astonishing 13.3 seconds at 105 mph, putting Hemis and LS6s on notice.

The secret lay in Buick’s expertise in building high-torque V8s. When GM’s ban on big-inch engines in intermediate cars expired in 1970, Buick built a high-compression 455 — and the results were spectacular: the base GS455 was rated at 350 horses and a neck-snapping 510 pound-feet of torque. And there was more: the factory Stage 1 package added higher-flowing heads, an aggressive camshaft, and higher numerical gears, resulting in a laughably underrated 360 horses and 510 pound-feet of twist.

Buick even built two Stage 2 prototypes, which improved the exhaust side of the engine: parts like new heads with two-inch exhaust ports, a revised cam, 11:1 compression, and headers were rumored to make 100 more horsepower — but the Stage 2 never saw production.

This sinister example is one of only 8,732 GS455 Coupes built in 1970. The seller purchased it in 1986, and after a reported restoration 20 years ago, it now represents what a factory Stage 2 build would have looked like. It has been refinished in black paint over black upholstery, with a Stage 2-style hood scoop. And the 455ci V8 was reportedly overhauled approximately 1,000 miles ago with a roller cam, ceramic-coated headers, and a three-inch exhaust system. That mill is backed by a three-speed Turbo Hydramatic transmission and a 4.10 positraction rear end.