In 1965, a high-performance version of the 273, with 10.5 compression, solid-lifter cam, and a Carter AVS four-barrel, joined the Valiant and Dart option lists. Rated at 235 hp at 5,200 rpm, the HP version added just shy of $100 to the bottom line. Over at Plymouth, the Barracuda, with its fastback styling, also was available with the optional 273 four-barrel V-8.

The year 1965 also saw the introduction of a limited production Dart model that could be ordered as the D-Dart; so named for the class of racing it was intended to participate in: D/Stock. This ultimate racing Dart would have its steel body panels replaced with fiberglass ones made for Dodge by a company called Fibercraft. The switch shaved 400 pounds off the car. A four-speed manual transmission with a Weber clutch and a Sure-Grip 8 3/4-inch rear with a 4.86:1 axle ratio was also part of the D package. A heavy-duty suspension rounded out the upgrades on cars that came to be called the D/Dart. Owners of ordinary Darts could contact Chrysler's Parts Division to convert their cars to a D spec.

Dodge called the D/Dart a "regular production line" car, but cautioned that "Due to the expected use of these vehicles, no warranty coverage applies."

In 1966, with a major re-do upcoming for 1967, new grilles were the only major change in appearance. An "S" version of the Dart (similar to the "Formula S" Barracuda) featured the hi-po 273, four-speed transmission, and plenty of heavy-duty chassis and suspension pieces offered as a factory option to make the cars competitive and legal in production-based racing classes at the drags and in road racing (most notably SCCA's A/Sedan class and in SCCA's Trans-American Sedan Challenge Series, which first ran in 1966).

Chapter Three
A major re-design marked the year 1967. The Dart and Valiant wagons were discontinued, and Plymouth moved hardtop and convertible A-Bodies into the Barracuda lineup, making the Valiant a sedan-only. This was the year that Chicago Dodge dealer "Mr. Norm" Kraus put a 383 into a '67 Dart hardtop, and then drove it to Detroit to show the Dodge Division brass that it could be done. Before the end of the model year, the 383 was a factory option in the Barracuda and Dart, without power steering.

In 1968, a new high-performance small-block-the 340-inch LA engine-joined the Dart and Barracuda option list. This was also the year the Dart GTS appeared. And to completely knock the wind out of Ford and Chevy at the dragstrip, 50 Dart hardtops and 59 Barracuda fastbacks were pulled off the Hamtramck assembly line as partial vehicles and shipped to Hurst for 426 Race Hemi conversions. That was also the year TV detective Mannix started driving a modified Dart GTS convertible.

In 1969, the Dart hardtop model was renamed Swinger. The budget-muscle Swinger 340 was added to the Dart lineup, alongside the Dart GTS. A 'Cuda option package was added to the Barracuda, while the Formula S package was dropped. The big 440 was offered as an option in the Dart GTS and 'Cuda models during the model run, alongside the 383. This was the last year for the boxtop two-door sedan body style and the 170-inch Slant Six.

Chapter Four
In 1970, the Duster coupe was added to the Valiant lineup and replaced the boxtop two-door sedan, and Dodge did likewise for the Swinger Special hardtop. A Duster 340 model appeared in the Valiant lineup, and the 318-inch LA succeeded the 273 as the standard V-8. Standard Slant Six displacement was stroked to 198 ci, and with the arrival of the E-Body that year, the 383 and 440 engine options (and all A-Body convertibles) were discontinued. Mannix switched to an E-Body convertible.

The year 1971 didn't see many design changes, but Dodge did get its version of the newly styled A-Body: the Demon. Also in 1971, the Valiant got its own version of a hardtop: the Scamp. This marked the first Valiant hardtop since 1966. The Demon 340 replaced the Swinger 340 in the Dart lineup.