trunk to free up room and improve weight distribution. Darts could be ordered with either a four-speed manual or three-speed automatic transmissions. Manual transmission equipped cars, code A-833, featured a Dana 60 built heavy-duty axle with a 4.88 gear ratio, heavy-duty clutch, steel bellhousing, and special torque shaft and pivots. Manual transmissions were modified by removing synchronizers which lowered the chances of missed shifts. A Hurst floor-mounted shifter came standard. The automatic transmissions were the then-new Chrysler-built 727 TorqueFlite three-speed with 8-3/4 inch large stem pinion center section with a 4.86 gear set, and a 2,600 rpm high speed torque converter. They were also modified with a floor-mounted Hurst shifter for manual shifting. Other features include heavy-duty rear shocks, heavy-duty radiator with a seven-blade fan, and deep groove pulleys, a high capacity oil pump, solid-lifter cam, and a roller timing chain to reduce stretch and provide more reliable performance. A transistorized dual points breaker distributor coupled with a Prestolite ignition and solid core wires were also used. The cars weighed approximately . The cars were designed to meet street legal requirements, but due to the modifications, the cars came with disclaimers that they were not for street use, but rather "supervised acceleration trials", or drag racing. 1969 The 2-door sedan was dropped at the end of 1968 and replaced with the Swinger 2-door hardtop for 1969 available in Custom, GT, and GTS trim. Also added was the Swinger 340. The entire 1969 Dart range received trim updates including another minor revision of the grille and a return to rectangular park/turn lights. The 1968 round side marker lights were replaced with rectangular reflectors. Head restraints were optional equipment until January 1, 1969, when their installation became mandatory under federal law. The 6-cylinder models received a carburetor anti-ice system borrowed from Canadian-market Chrysler 6-cylinder engines, and the drum brake automatic adjusters were revised for more consistent operation. At the top of the Dart performance range for 1969, there was limited availability of the 440 V8 in the Dart GTS model. 1970 The Dart was refreshed for 1970 with front and rear changes designed to bring the car closer to the design themes found in Dodge’s full-size vehicles through grille and contour changes. In the rear, the Dart’s new rectangular tail lights were set into a wedge-shaped rear bumper design continuing the angled trailing edge of the new deck lid and quarter panels.