Buick GS Stage 1-1970 images

Buick spent the 1960s building the most civilized cars in GM’s performance catalog, then produced a 455 that made more torque than anything else on the American market. The Stage 1 package was ordered by relatively few buyers and was almost certainly underrated by the factory on purpose. This Gateway Classic Cars gallery shows one. Read on for why the torque figure mattered more than the horsepower number.

1970 Buick GS Stage 1 455 CID V8 Turbo 400

MCF thanks Gateway Classic Cars for the images provided here.

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Buick had a reputation problem in 1970, and it was entirely of its own making. The division had spent two decades building large, quiet, well-upholstered cars for people who had already arrived somewhere in life, which was excellent business and terrible branding for anyone trying to sell a muscle car. So when the Gran Sport 455 with the Stage 1 package showed up on dealer lots that year and proceeded to embarrass considerably more famous machinery at stoplights across the country, most of the country did not find out for another thirty years. The car in this Gateway Classic Cars gallery is that car, and the argument for it rests almost entirely on a single number that has nothing to do with horsepower.

Flint’s Reputation Problem

That reputation was not undeserved, and Buick had spent real money building it. The division sat one rung below Cadillac in General Motors’ carefully managed brand hierarchy, above Pontiac and Oldsmobile, and its product planning reflected that position in every decision. Buick interiors were quieter, the ride was softer, the styling was more restrained, and the advertising spoke to buyers who had stopped needing to prove anything. None of that is a natural foundation for a muscle car, and when Buick did build one, the badge worked against it in exactly the demographic most likely to buy it. Teenagers in 1970 were not walking into a Buick showroom, which is precisely why the ones who did tended to surprise people.

The Displacement Cap Falls

Getting there required a corporate policy change. Through the late 1960s, General Motors capped the engine displacement its intermediate-sized cars could carry at 400 cubic inches, which meant Buick’s Gran Sport had been fighting with one hand tied behind its back. The division had a 455 cubic inch V8 available in its full-size cars and no legitimate way to put it in the mid-size Skylark-based Gran Sport. For 1970 the cap was lifted across the corporation, and every GM division responded within months. Buick’s response was to drop the 455 straight into the GS and then offer a package that made it considerably more than a displacement upgrade.

Inside the Stage 1 Package

The Stage 1 package was a genuine performance specification rather than a badge. It brought a higher compression ratio, cylinder heads with larger valves, a more aggressive camshaft profile, a specifically calibrated four-barrel carburetor, and revised exhaust breathing, along with a heavy-duty cooling system and a specific rear axle ratio to suit. Buick also fitted a functional cold-air induction hood on GS models, which fed outside air directly to the carburetor through hood-mounted openings. None of this was subtle engineering. It was simply engineering that arrived wearing a Buick badge, which is why so few people were paying attention.

The Torque Number That Ended Arguments

The torque figure is what settles the argument. Buick quoted the Stage 1 at 360 horsepower and 510 lb-ft of torque, with peak torque arriving at just 2,800 rpm. That combination is unusual even by the standards of an era full of big-displacement engines, and it fundamentally changes how the car behaves. A high-revving small block needs the driver to work for its performance. An engine making over 500 lb-ft just above idle does not need to be worked at all. It simply leaves, from any speed, in any gear, which is exactly the characteristic that makes a car frightening to line up against on a public road. Contemporary magazine testing recorded quarter-mile times in the 13-second range, which put the Stage 1 among the quickest cars any manufacturer sold that year.

Gran Sport, GS 455, and GSX

The model naming can be confusing, so it is worth untangling. The Gran Sport, commonly shortened to GS, was the performance version of the Skylark. For 1970 the GS 455 designated a car with the big engine, and Stage 1 was an additional performance package on top of that. Above all of it sat the GSX, which was primarily an appearance and equipment package available in a very limited palette, most famously Saturn Yellow and Apollo White, with bold stripes, a rear spoiler, a hood-mounted tachometer, and a specific instrument package. A GSX could be ordered with or without Stage 1, which means a Stage 1 car is not necessarily a GSX and a GSX is not necessarily a Stage 1.

The Rating Nobody Took at Face Value

Almost nobody believed the horsepower rating at the time and nobody believes it now. Period magazine testers, Buick insiders, and every dyno operator who has put one on a machine since have all pointed toward real output substantially higher than the quoted 360, with estimates commonly landing in the low-to-mid 400s in gross terms. This was standard industry practice rather than a Buick eccentricity. Insurance underwriters priced policies off published horsepower figures, and every manufacturer with a fast car had a strong financial incentive to publish a modest one. The Stage 1 was simply one of the more egregious examples of the practice.

What It Was Actually Like to Drive

Driving one is a strange and specific experience that does not resemble any of its rivals. The car is heavier and better isolated than a Chevelle or a Road Runner, the interior is noticeably nicer, and at cruising speed it behaves like exactly what its badge says it is. Then the throttle goes down and the whole thing simply picks up and goes, without drama, without needing a downshift, without the frantic quality that defines a lot of period muscle cars. It is fast in the way a modern turbocharged car is fast, which is not a comparison anyone would have made in 1970 but which explains why the Stage 1 has aged so much better than its contemporaries as a car to actually use.

Rarity, Verification, and Value

Production was modest. Only a few thousand Stage 1 cars were built across GS and GSX models for 1970, and the survival rate for cars that spent the 1970s being driven by people who knew what they had is not high. Verification runs through the cowl tag, the engine code, the correct Stage 1 specific components, and whatever build documentation has survived. The market has caught up considerably over the past two decades as the Buick’s reputation has been rehabilitated, but a documented Stage 1 still frequently trades below a comparably documented Chevelle or GTO of the same year, which says more about badge recognition than about the cars. Anyone shopping GM intermediates from 1970 owes it to themselves to drive one before deciding.

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