1966 Dodge Dart Is an Unassuming Sleeper With a Big-Block Surprise

The compact Dart wasn't much of a performer in the early days. Designed with fuel efficiency in mind, the vehicle came with a 101-horsepower six-cylinder as standard. A bigger mill with a similar cylinder configuration provided 145 horses.

Dodge also offered an optional V8, but the 273-cubic-inch (4.5-liter) LA-block sent only 180 horsepower to the rear wheels in 1964. Output increased to 235 horses in 1965.

The 1967 redesign brought the first big-block V8 under the hood. The optional 383-cubic-inch (6.3-liter) unit debuted with 280 horsepower and reached the 300-horsepower mark in 1968. The Dart reached its performance peak in 1969 when the 440-cubic-inch (7.2-liter) found its way into a limited-edition GTS model.

Unlike the midsize Dodges of the era, the Dart never got the mighty 426-cubic-inch (7.0-liter) HEMI. Yes, you could point out the 1968 L023, which was equipped with the said mill, but it doesn't really count since it was a factory dragster rather than a streetable machine (Dodge made 80 of them)

All told the early fourth-generation Dart (1967-1972) is by far the most desirable variant in terms of design and performance. If you're a fan of the third-gen version (1963-1966) and its quirky styling and lighter setup, you're pretty much stuck with low-output engines. Or you can do what some enthusiasts do and opt for a big-block swap.

The 1966 two-door hardtop you see here may look like a mundane Dart on the outside, but it packs a big-block surprise under the hood. One that's bigger than the 383 B-type mill Dodge introduced in 1967. This lump displaces 400 cubic inches (6.6 liters), and it looks like it's almost too big for the Dart's relatively cramped engine bay.

It's unclear what type of V8 we're looking at, but it looks a lot like the engine Chrysler introduced in 1972 as a replacement for the venerable 383. It was largely similar to its predecessor but delivered lower output to meet then-new fuel emissions standards.

It was used in various Chrysler vehicles, including retiring muscle cars like the Dodge Charger and Plymouth Road Runner. The mill was discontinued in 1979 as Mopar's final big-block V8.

The 400 wasn't as potent as the 383. In its early years, the range-topping, high-performance version came with 260 horsepower on tap. But it also became a popular choice for beefed-up builds due to its large bore size and short deck height. So, I wouldn't be surprised if this Dart had more than 400 horsepower to lay on the ground.

If it does, it's one heck of sleeper because it looks fairly stock apart from the blacked-out front grille and rear fascia trim and the wider tires. The rear wheels are notably fatter, a sign that this Dart could be a solid performer at the drag strip.

Granted, it's not the sleekest build out there, but it's proof that a mundane third-generation Dart can become a proper muscle car without a significant overhaul. Check it out in the video below.