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 112 in (2,845 mm), 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. 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.