Changes for 1968 were relatively subtle. The park/turn lights in the grille were moved slightly inboard and made round. Side marker lights lights were added to the front fenders and rear quarter panels, to comply with newly introduced Federal Motor Vehicle Safety Standard 108. Other changes to comply with new federal safety laws included collapsible steering columns, additional padding on the dashboard and sunvisors, shoulder harnesses (separate, this year and until 1973, from the lap belts) and non-glare matte finish on the windshield wiper arms. Chrysler's "Clean Air Package" emission control system became standard equipment on cars sold in all 50 states. The steering linkage was revised again, as were the windshield and rear window gaskets and trim-lock strips, leaving the 1967 pieces as one-year-only items. The standard rear axle ratio was dropped from 2.93 to 2.76 with all standard-performance engines and automatic transmission. Part-throttle downshift functionality was added as a refinement to the TorqueFlite automatic transmission in 6-cylinder cars, to retain acceptable city performance with the taller rear axle ratio.
Fifty specially-equipped "Hemi Dart" models were built under subcontract by Hurst for NHRA SS/B and SS/BA drag racing classes, today these cars (with their sister Plymouth Hemi'Cudas) remain the quickest production cars ever mass produced, with elapsed times in the low 8-second range (1/4-mile) and trap speeds approaching 160 MPH.
Source: Wikipedia, 2012