The Buick Skylark had a new option package arrive for the 1965 model year. The Gran Sport package included a 325-horsepower, 401 cubic-inch Nailhead V8 (although it was called a 400 in the Skylark to skirt a General Motors rule prohibiting midsize car engine displacement to 400 cubic inches). More than 15,000 Buick Skylark Gran Sports rolled off dealer showrooms for 1965, and nearly as many for 1966. In 1967, Buick made the option package a standalone model called the Buick GS 400, featuring a new 400-cube V8 that made 340 horsepower.
1968 brought a major revamp for the Buick GS. The GS was available as a two-door hardtop called a Sport Coupe and as a convertible. The wheelbase was three inches shorter at 112. The bodywork had more curves, with a body detail line that started at the headlights and arced downward to the rear wheel well, and a concave rear bumper. The roofline on the hardtop had a fastback appearance, and the grille had a chrome surround with a blacked-out center.
Little changed from the 1968 revamp, as the 1969 Buick GS could be had in either convertible or hardtop configuration. The standard engine was a 400 cubic-inch V8 that made 340 horsepower. The optional Stage 1 package had 10.25:1 compression, functional hood scoops with ram air-style cold air intake, a Rochester Quadrajet four-barrel carburetor, and dual exhaust that bumped output to 350 horses. The Stage 2 package had even higher compression at 11.0:1, a more radical cam, a Holley 850 cfm carb, Edelbrock intake, and Mickey Thompson headers, all of which combined to produce 450 horsepower.
Retired Buick engineer Dennis Manner was quoted in Hemmings Muscle Machines as saying, “The whole Stage 2 package was worth about a half second over the Stage 1 and made 100 hp more.” Backing the GS Stage 1 and Stage 2 were a standard three-speed manual transmission with a 2.42 rear gearset, an available four-speed manual with a 3.42 or optional 3.64 rear gear, or the three-speed Turbo-Hydramatic automatic transmission with either a 2.93 or optional 3.42 rear gear. The Stage 2 cars were equipped with a staggering 4.78 rear diff. Both Stage 1 and Stage 2 cars had standard Buick Positive Traction.
Our feature 1969 Buick GS Stage 1 convertible is a documented three-owned car finished in Verde Green over Sandalwood vinyl. It is powered by its matching-numbers 400 cubic-inch V8 backed by an automatic transmission. It is well equipped with power steering, power brakes, power windows, bench seats, and a power convertible top. Included in the sale of this GS are the Protect-O-Plate, documented build information from GM of Canada, bill of sale, comprehensive restoration documentation, pictures, and wire wheel covers.
This 1969 Buick GS 400 Stage I convertible will cross the Mecum Auctions block at their Summer Special in Kissimmee, Florida July 6th through the 9th.