Plymouth ‘Cuda 1970 – 340 Convertible

Plymouth built somewhere around 550 ‘Cuda convertibles for 1970, and only 262 of them carried the 340 four-barrel. Narrow that by transmission and paint code and the surviving population gets very small very quickly. This EB5 Blue Fire Metallic car sits at the intersection of all of it — and the engine that made it rare at the time is the one enthusiasts now argue was the best choice in the catalog.

Order sheets from 1970 tell a story most Plymouth dealers never had to explain twice: hardly anyone buying a ‘Cuda convertible that year chose the 340. Buyers chasing headline horsepower reached for the 440 Six Barrel or the 426 Hemi, and the smaller-inch V8 became an afterthought that showrooms barely stocked. That collective decision, made across a few hundred individual transactions more than half a century ago, quietly turned what should have been the common configuration into one of the scarcer ones. Layer on a specific paint code and a specific transmission and the odds of finding a matching-numbers survivor start to look almost accidental. Which raises an obvious question about whether those buyers were right.

How Rare Is Rare, Exactly

The production figures set the scene. Plymouth built roughly 550 ‘Cuda convertibles for the 1970 model year — Mopar records do not fully agree on an exact count — and just 262 of them carried the 340 with a four-barrel carburetor. Of that group, only 88 were paired with a four-speed manual and a mere 19 with a three-speed. Filter further by a color like EB5 Blue Fire Metallic and you are working with a handful of cars, some of which have long since been lost to rust, accidents or half-finished restorations. Rarity in the Mopar world is almost always this granular.

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Why the 340 Was Secretly the Right Answer

The irony is that the 340 has aged into the connoisseur’s choice. It was rated around 275 horsepower on the gross scale and built with genuinely serious internals for a small-block: a forged crankshaft, a double roller timing chain and free-flowing heads. What separates it from the big-blocks is not peak output but where the power lives. The 340 revs, and it does so happily, in a way the 440 and the Hemi simply do not. It also weighs meaningfully less, and all of that weight comes off the front axle.

What the Small-Block Did for a Drop-Top

That matters more in a convertible than almost anywhere else. E-body convertibles gave up structural rigidity when the roof came off, and adding a big iron block over the front wheels made the handling deficit worse. A 340 ‘Cuda convertible steers and changes direction in a way its big-block siblings never managed, and contemporary drivers who cared about more than a quarter-mile time picked up on it. Those buyers were in the minority in 1970. They look considerably smarter now.

1970 and the Birth of the ‘Cuda as Its Own Car

1970 was also the year the ‘Cuda became its own thing. Plymouth had been selling the Barracuda since 1964, first as a fastback Valiant derivative and then as a more distinct car, but for 1970 the third-generation E-body arrived on a wider, shorter platform shared with the Dodge Challenger. The performance versions were split off under the ‘Cuda name with their own hood treatments, badging and engine availability, while the standard Barracuda and the luxury-trimmed Gran Coupe continued alongside. It is why enthusiasts are so particular about the apostrophe.

A Two-Year Window for the Convertible

The convertible existed in that form for only two model years. Plymouth offered a ‘Cuda convertible in 1970 and 1971 and then dropped it, leaving the hardtop as the only body style through the car’s final years. Combine a two-year window with an option that few buyers selected and you have the structural reason these cars are hard to find rather than merely desirable. It is worth noting that this same period produced Chrysler’s High Impact colors — In-Violet, Vitamin C, Lemon Twist, Tor-Red — which is why a subtler metallic like EB5 stands out among survivors.

Reading the Fender Tag Before You Believe Anything

All of which makes verification essential. The fender tag and, where it exists, the broadcast sheet are the documents that separate a genuine 340 convertible from a clone built out of a base Barracuda. Engine casting numbers and dates need to line up with the car. The value gap between an authenticated matching-numbers example and a well-executed tribute is large enough that fakes are a real and ongoing problem in this corner of the market, and a seller who cannot produce paperwork is asking you to pay a documented-car price on faith.

Where E-Bodies Rust and What It Costs

Condition deserves the same scrutiny. E-bodies rust in predictable places: the lower rear quarters, the floor pans, the trunk drop-offs and the rear frame rails, and convertibles add the extra complication of the top well and its drains. Sheet metal is available, but the labor required to do it correctly on a car with no roof to hold it square is considerable, and a bad repair on a convertible shows up as doors that will not shut and a body that flexes over bumps.

Inside a 1970 ‘Cuda Convertible

The cabin is worth a look too, because the 1970 ‘Cuda’s interior options say a lot about who the car was aimed at. Buyers could specify the Rallye instrument cluster with its full complement of gauges rather than the base car’s warning lights, and four-speed cars could be ordered with the pistol-grip shifter that has become one of the most recognizable pieces of Mopar hardware ever made. High-back bucket seats, a console, woodgrain trim and a rim-blow steering wheel were all available. On a convertible finished in a metallic blue with matching interior, that combination produces a car that looks considerably more expensive than its base price suggested, which was precisely the intent.

What a Documented Car Represents Today

What a properly documented example represents, then, is the intersection of several unlikely decisions: a buyer in 1970 who chose the smaller engine, a color that was not one of the attention-grabbing High Impact shades, a body style built for only two seasons, and fifty-plus years of survival in a chassis that rusts eagerly. Any one of those is unremarkable. All of them together, on one car, with paperwork to prove it, is what separates a headline consignment from an ordinary Barracuda. It is also why buyers at this level spend as much time reading tags as they do looking at paint. Let us know what you think of this one in the comments below.

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