Buick GS Convertible

Perhaps the 1970 GS Stage 1’s status as Buick’s most powerful street machine fueled their enthusiasm for record-keeping. It carries, after all, the A-1 (aka Stage 1) option: the 360-hp, 455-cu. in. big block V-8 with dual exhausts, a 3.64:1 Positraction rear axle and heavy-duty radiator.

Buick introduced the Stage 1 package as an assembly line upgrade to its 1969 GS 400-cu. in. V-8. The benefits of adding Stage 1’s special Quadrajet carburetor, functional cold-air scooped hood, high-lift camshaft, 2.25-inch exhaust, and 3.64:1 gears was far greater than the advertised five-horsepower boost to a ridiculously underrated 345 horsepower.

For 1970, Buick squeezed its 455-cu. in. V-8 between the GS fenders and once again offered a Stage 1 option with components similar to the previous year’s equipment. In Stage 1 form, the 455 GS engine put out 360 (underrated) horsepower and a staggering 510 lb-ft of torque. To give an idea of the accolades heaped on the mighty Buick, Hot Rod declared it “Mr. Muscle of 1970.” In the quarter-mile, a GS Stage 1 could fly through the lights in the 13-second range at more than 100 miles per hour.

Buick built 10,148 GS cars with the 455-cu. in. V-8 in 1970, only 1,416 of which were convertibles; even fewer carried the Stage 1 designation and sported a four-speed transmission. With its black vinyl top and matching bucket seat interior, Robson’s GS is a very rare combination of standard and optional equipment.

This car was auctioned off by RM Auctions in November of 2010 at the Robson Estate, Gainesville, Georgia.

360 hp, 455 cu. in. V-8 engine with 10.5:1 compression and a high lift camshaft, four-barrel carburetor, four-speed manual transmission, heavy duty suspension with front and rear Firm Ride springs, Positraction rear end, four-wheel disc brakes. Wheelbase: 112"

Source: RM Auctions
Photo Credit: Copyright Darin Schnabel

Gallery: Buick GS Convertible