long-lived; while 1962 was the only year for a B-body model named "Dart", the B platform remained in use with only very slight modification and a few new letter designations through to the 1981 R-body cars. Third generation (1963–1966) For 1963, Dodge made a last-minute decision to drop the Lancer name in favor of Dart for Dodge's newly designed "senior compact", a marketing term referring to the wheelbase having grown to from the Lancer's . This longer wheelbase used the same A-body suspension of the Valiant and defunct Lancer, and would underpin all Darts from 1963 to 1976 except the 1963–1966 station wagons which used the Valiant's ( wheelbase) and the 1971–1976 Demon/Sport which used the Plymouth Duster's wheelbase. The longer wheelbase gave more rear seat legroom than the previous Lancer or the contemporaneous Valiant. The Dart was available as a 2- or 4-door sedan, a 2-door hardtop coupe, a station wagon, and a convertible. Three trim levels were offered: the low-spec 170, the high-spec 270, and the premium GT, which was available only as a 2-door hardtop or convertible. The 1963 Dart has a turning diameter of . The Dart was an instant market success, with 1963 sales up sharply compared to those of the 1962 Lancer. The Dart remained extremely popular through the end of the Dart's production run in 1976 in comparison to the Ford Falcon and the Chevrolet Nova. Initial engine offerings were two sizes of the slant-six: a , version was fitted as standard equipment, and a , version was available for less than $50 extra. The aluminum engine block for the 225 was discontinued early in the 1963 model year. After the start of the 1964 model year, an all-new, compact, lightweight LA V8 producing with a 2-barrel carburetor was introduced as the top engine option. 1964 was the last year for pushbutton control of the optional Torqueflite automatic transmission, so 1963 and 1964 models were the only compact Darts so equipped. Standard axle ratios in 1964 were 2.93:1 with automatic transmission and 225 engine, or 3.23:1 with manual transmission and 225 engine, or with 170 engine and either transmission. A 3.55:1 ratio was optional. New features included stronger door locks and a refined automatic choke. In 1965, the 2-barrel 273 remained available, but a new performance version of the 273 engine was released with a 4-barrel carburetor, 10.5:1 compression, a more aggressive camshaft