Styling changed dramatically on the 1968 Buick GS, specifically the length and wheelbase, along with changes in the rear end and side moldings. This was due to the platform change to the A body platform. The wheelbase lost 3 inches, and the overall length shrunk by 4.4 inches. Creased side moldings and the rear styling added considerable weight to the model, and with the 400 engine staying in the top model, performance dropped slightly.
1968 Buick GS 350
The "Jr" engine was beefed up a bit for the 1968 model year, and the car was now called the "GS 350", with it teaming up with an upgraded engine and 10 extra ci's. The 10 ci increase was due to a slight increase in the engine bore. Sales doubled for the GS 350, and the new "California GS" option was now available to the rest of the country.
1968 Buick California GS
For the first time in mid model year 1968, Buick made the California GS available to the rest of the country. The California GS was not included in Buick’s full size catalog, but it was advertised in a two page black and white brochure at Buick dealerships. Like the 1967 model, the 1968 California GS had special “California GS” badges on the rear fenders, and bench seats and the Super Turbine 300 Transmission were the only choices. Chrome plated wheel covers, a chrome covered air cleaner lid, a vinyl top, and a deluxe steering wheel were included in this special model.
1968 Buick GS 400
Other than the few exterior cosmetic changes, The 1968 GS 400 did not change much. The engines stayed the same, and sales nearly doubled over 1967 sales, even with all the new muscle car models being introduced by nearly every American auto manufacturer. As the only muscle car Buick would build during the muscle car era, the GS 400 was holding it’s own, and more horsepower would be offered mid model year with the “Stage 1” option.
1968 Buick GS Stage 1
By mid model year, Buick raised the bar with the newly released “Stage 1” option. This option was offered through 1973, but was a very rare option for the 1968 model year since it was offered mid year, and was a very expensive dealer installed option for 1968. The Stage 1 option added a hatter cam, 11.0:1 compression, stronger valve springs, and a better transmission. Official Buick numbers give the Stage 1 option 5 extra horsepower, but considering the Stage 1 dropped the ¼ mile times down by a second or more, 5 extra horsepower probably isn’t accurate. Many experts believe about 80 extra horsepower was achieved with the Stage 1.