GS 400, GS 340, AND THE CALIFORNIA GS
Buick’s next-generation big-block V8 finally debuted for the 1967 model year. The new engine was developed by Dennis Manner and Cliff Studaker, who had worked with Joe Turlay on the design of the Nailhead while still a student engineer. The Nailhead’s pentroof combustion chamber was discarded in favor of a domed wedge shape, in some respects an elaboration of the design used by the old aluminum small block.
There were initially two versions of the new V8. One was 430 cu. in. (7,041 cc), replacing the 425 in the Riviera and full-sized cars, while the other, intended specifically for the A-body, was 400 cu. in. (6,554 cc). (Both engine had the same 3.90-inch (99.1mm) stroke, but the 400 had a narrower bore.) The new engine was about the same overall size as the old and retained the same bore spacing, leading several observers to note adopting the old engine’s bore would bring displacement to an impressive 455 cu. in. (7,468 cc).
The new engine was not dramatically more powerful than the old, but had better breathing, allowing similar output with a milder cam and smaller carburetors. The new 400 was rated now at 340 gross horsepower (254 kW) while the 430 claimed 360 hp (269 kW) with a single four-barrel carburetor, matching the discontinued dual-carb Super Wildcat. Both versions were mildly tuned and there was potential for considerably more power.
The Skylark Gran Sport was now abbreviated “GS” and was available both in big-block GS400 form and as a less-expensive GS340 hardtop, powered by the small-block 340 cu. in. (5,574 cc) engine. The latter was naturally tamer than the GS400, but was usefully cheaper and commensurately easier to insure.
The GS400, fortified with the new engine and the newly optional three-speed Super Turbine 400 (Turbo Hydra-Matic) transmission, was considerably stronger than previous big-engine Skylarks. It still wasn’t as fast as the hottest Ram Air GTOs, but it was now a match for the Oldsmobile 4-4-2 or Chevrolet SS396. Front disc brakes were newly available, which gave the Buick a much better chance of slowing down.
This newfound muscle did little to invigorate sales. Buick sold only about 17,500 GS400s in 1967 along with about 3,700 GS340s. The division had given up on the Wildcat Gran Sport, although most of the pieces could still be ordered separately, and the Riviera GS accounted for fewer than 5,000 sales.
If Buick was not exactly redefining the Supercar genre, it also wasn’t suffering. While sales of the A-body Special and Skylark were unimpressive, Buick’s 1967 market share was higher than it had been in a decade. Buick hadn’t done any particular damage to Pontiac sales, but it had taken a chunk out of Oldsmobile; in 1967, Buick edged out Olds for fifth place in total U.S. sales.
Buick restyled its midsize cars in 1968, abandoning the crisp lines it had favored since 1961 for a curvier, massive look with semi-skirted rear wheels and a revival of Buick’s old side spear trim. The new idiom was hardly sporting, but it made the intermediates look more like full-sized Buicks. Buick A-body sales rose more than 10% for 1968, which spoke volumes about the priorities of the typical Skylark buyer. (Technically, the Gran Sport was no longer a Skylark. Buick belatedly followed the lead of Pontiac and Oldsmobile and made it a separate series in GS350 and GS400 forms.)
The new GS400 may have looked a trifle effete, but there were encouraging noises from the engine compartment. Buick engineers had been working with Bill Trevor, an instructor at the GM Training Center in Burbank, California, and their unofficial liaison to the Southern California drag racing community. By late 1967, an array of decidedly racy hardware was appearing in Buick parts lists: hotter camshafts, oversize main bearings with four-bolt caps, lightweight pushrods, heavy-duty oil pumps. Presumably hoping to capitalize on the much-publicized multi-stage rockets used in the Gemini and Apollo space programs, Buick packaged much of this equipment into “Stages”: a reasonably streetable Stage 1 and a track-bound Stage 2 setup, available through the parts departments of knowledgeable dealers. Before long, there was even a cold-air intake system, comparable to Pontiac’s Ram Air set-up.
Despite the Stage 1 and Stage 2 packages, the GS400 still seemed a trifle ambivalent about its Supercar mission. Without the dealer-installed accessories, it was no more powerful than the 1967 GS400 and the new body was somewhat heavier. In standard form, the GS400had still a typically Buick-like ride and the interior remained innocent of gauges or other sporty touches. The GS350, powered by a new 350 cu. in. (5,724 cc) small-block V8 with 280 hp (209 kW), was even more sedate.
The inevitable result was that Buick was again the poor relation among GM’s intermediate Supercars, selling 21,514 units (plus an unknown number of California GS models) compared to almost 34,000 4-4-2s, nearly 88,000 GTOs, and around 60,000 Chevy SS396s. Buick’s overall sales, however, were up 15%, the division’s second-best year.
The 1969 Buick intermediates were more of the same, although the Stage 1 engine was now a factory option, as was the Cool Air system with its functional hood scoops. So equipped, a GS400 was capable of running the quarter mile in the high 14-second range with trap speeds over 100 mph (161 km/h), better than most stock GTOs. Pontiac buyers paid little heed; Gran Sport sales fell to just over 13,000, about a third of those the tame GS350.
The fact that Buick didn’t simply throw in the towel at that point says a great deal about the appeal of the Supercars to contemporary automakers. From a manufacturing standpoint, a car like the GTO or GS400 differed very little from a workaday Tempest or Skylark and the added cost of the unique trim, springs, and other components was seldom more than a few dollars. However, the performance model commanded a significantly higher price. Since most of the really expensive equipped was optional, its cost could be passed directly to the customer with a healthy margin tacked on for good measure. If the GS400 had had a unique body and running gear, it would have been a money loser, but the investment was so low that the division could make a profit even at lower volumes.
We assume that’s the reason Buick’s new general manager, Lee Mays, didn’t cancel the slow-selling GS when he replaced Bob Kessler in April 1969. Mays, who had been general sales manager of Chevrolet until he clashed with new general manager John DeLorean, was a conservative salesman of the old school and reportedly had little affection for specialty cars. At Chevrolet, he had opposed the Monte Carlo, which later proved to be one of the division’s most profitable products. Nonetheless, the GS earned an encore for 1970. It would be one of the most audacious models in Buick’s long history.