}} The 1968 model year was one of significant change for the Buick Skylark. Although still using the same basic chassis, all of GM's mid-sized cars adopted a policy of using two different length wheelbases. Two-door models used a shorter wheelbase of , while four-door models used a longer wheelbase of 116 in (the
Buick Sport Wagon and
Oldsmobile Vista Cruiser used an even longer wheelbase of 121 in). All of GM's mid-sized cars received all-new sheet metal, incorporating a semi-
fastback appearance, which was a revival of a
streamlining on all GM products from 1942 until 1950 as demonstrated on the
Buick Super Club Coupe (sedanette), that showed influences from the restyled
Riviera. More Federally mandated safety features improved occupant protection and accident avoidance, including side marker lights, shoulder belts (on all models built after January 1, 1968), and parking lights that illuminated with headlights. The
Buick Gran Sport, previously an option package available on the Skylark, became a separate series, starting with the 340 hp/440 lbs torque 400 c.i.d. V8 1968 GS 400, using the 2-door Skylark body and chassis. In a reshuffling of models in the lineup, the Special Deluxe replaced the previous Special. The Skylark nameplate was shuffled down a notch to replace the previous Special Deluxe. The previous Skylark was replaced by a new Skylark Custom. The basic Skylark was available as a two-door hardtop coupe or a four-door sedan. The Skylark Custom came as a two-door convertible coupe, two-door hardtop coupe, four-door hardtop sedan, or four-door sedan. The previous V6 was discontinued and the associated tooling was sold to Kaiser Industries, which used the V6 in its Jeep trucks and sport utility vehicles. The base engine in Buick Skylarks (and Buick Special sedans) became a 250-cubic-inch Chevrolet
I6, that produced at 4200 rpm using a single-barrel Rochester carburetor. Optional on the Skylark and standard on the Skylark Custom was a new 350-cubic-inch V8 derived from the 340, using a two-barrel Rochester carburetor that produced at 4400 rpm. The Buick Special name was dropped after the 1969 model year. A locking steering column with a new, rectangular ignition key became standard on all 1969 GM cars (except
Corvair), one year ahead of the Federal requirement. For 1970, the mid-sized Buicks once again received new sheet metal and the Buick Skylark name was moved down another notch, replacing the previous entry-level Buick Special. It was available in two- and four-door sedans with the 250-cubic-inch inline-six as standard and the optional 350-cubic-inch V8 (260 horsepower at 4600 rpm). Two-door models shared their roofline with the 1970
Chevelle, distinct from that of the shared
Pontiac LeMans and
Oldsmobile Cutlass. The two-door sedan was unique to Buick, sharing its roofline as the hardtop but having a thick
"B" pillar, with Buick's traditional "
Sweepspear" feature appearing as a crease running the length of the vehicle. Chevrolet did not offer a pillared coupe for the Chevelle from 1970 to 1972; all two-doors were hardtops. Replacing the previous Buick Skylark was the Buick Skylark 350, available as a two-door hardtop coupe or four-door sedan with the 350-cubic-inch V8 as standard equipment. This 350-cubic-inch engine was a different design than the Chevy's 350 CID engine (4.000 in × 3.48 in) the Buick design had a longer stroke and smaller bore (3.80 X 3.85 in) allowing for lower-end torque, deep-skirt block construction, higher nickel-content cast iron, crank main journals, and connecting rods, the distributor was located in front of the engine (typical of Buick), the oil pump was external and mounted in the front of the engine, the rocker arm assembly had all rocker arms mounted on a single rod and were not adjustable. The Skylark Custom continued to be available, also using the 350-cubic-inch V8 as standard equipment and still available as a two-door convertible coupe, two-door hardtop coupe, four-door hardtop sedan, and four-door sedan. Buick Gran Sport models continued to be available as a separate series. The Buick Sport Wagon name was now used on a conventional four-door station wagon that no longer featured a raised roof with glass panels over the cargo area, or a longer wheelbase, as in the past. It now used the same wheelbase as the Buick Skylark four-door sedan and the now-discontinued Buick Special four-door Station Wagon. It became, in effect, a Buick Skylark four-door station wagon in all respects but the name. For the 1971 model year, the base Skylark was available only with the
inline-6, now only putting out due to emission control devices, but in a two-door hardtop coupe body-style (in addition to the previous two- and four-door sedans). The Skylark 350 had a V8 engine that put out only . It was now available as a two-door sedan in addition to the previous two-door hardtop coupe and four-door sedan. 1972 was the last model year for the mid-sized Buick Skylark. During this model year many pollution controls were added to the engines, Compression was lowered, engines had to accept leaded and unleaded gas, and spark timing was retarded (no vacuum advance in lower gears) while driving in lower gears to reduce emissions. For 1972, the base Buick Skylark used the 350-cubic-inch V8 with the 2-barrel Rochester carburetor (now putting out 145 horsepower) as standard equipment. A new federally mandated system to calculate power was put into effect that year, and the actual engine performance was probably comparable but slightly lower because of pollution controls in the 1972 model year to the that was listed for the previous year. The Skylark 350 now used a version of the same V8 engine as the base Skylark, but with a 4-barrel Rochester carburetor that generated . Skylark Customs were available with the same 350-cubic-inch V8 engines available in the basic Skylark and the Skylark 350. The Custom had an upgraded interior and dash with some extra chrome. Convertibles only came in the Skylark Customs and the Skylark 350s.
Engines •
Chevrolet "six" I6 (1968–71), supplied by Chevrolet •
Buick small-block V8 (1968–72, 1968–72 Sport Wagon, 1968–69 California Gran Sport, 1968–69 Gran Sport 350, 1970–71 Gran Sport, 1972 Gran Sport 350) •
Buick big-block V8 (1968–69 GS 400, 1968–69 Sport Wagon 400) •
Buick big-block V8 (1970–72 Gran Sport 455) ==(1973–1974) Skylark Hiatus==