Plymouth Killed the Barracuda’s Six-Barrel 340 in 1971 — Then Gave the Last ‘Cuda Its Only Quad Headlights

Peter Swainson’s private Mopar collection includes a run of 1969-1971 Challengers and ‘Cudas, with a handful crossing the block at Mecum’s record $193 million Indy sale. Here’s why the final year of the Barracuda’s E-body run — the one with the engine options stripped away — is the one collectors want most.

Plymouth spent 1971 taking things away from the Barracuda. The six-barrel 340 that defined the AAR ‘Cuda a year earlier was gone. The engine lineup was already thinning out. Production of the Hemi ‘Cuda, rare in 1970, was about to wind down for good. And yet collectors who chase E-body Mopars today will tell you 1971 is the year to find — not despite what Plymouth took away, but because of the one thing it gave the car that no other year ever got: four headlights, worn for exactly one model year on a body that would never wear them again. A walkthrough of one of the largest private Mopar collections in the country, assembled over decades by collector Peter Swainson and filmed ahead of Mecum’s record-setting 2026 Spring Classic, makes the case in person — rows of Challengers, GTXs, Road Runners, and a run of 1969-1971 ‘Cudas parked side by side under one roof.

A Collection Built One Car at a Time

Mecum’s Chris Jacobs walks the showroom floor with Swainson, a longtime friend of the auction house, as the two make their way past a collection built from Chrysler’s late-muscle-era output almost exclusively. A handful of the cars on camera — a run of 1969-1971 Mopar E-bodies — were pulled from the collection to cross the block at Dana Mecum’s 39th Original Spring Classic, held May 8-16, 2026, in Indianapolis. That auction went on to post the best nine days in the house’s history: more than 2,600 lots sold at a 76% clearance rate for a combined $193 million, making it one of the largest single collector-car sales ever held.

The comment section underneath the video turned into its own small reunion. Viewers who had owned, restored, or walked away from specific Mopars decades ago showed up to share their own near-misses — one recalling passing on a 440 six-pack, four-speed ‘Cuda for a few thousand dollars in the 1990s, others swapping notes on which of Swainson’s cars they remembered from earlier owners or earlier auctions. It’s the kind of response that tells you this isn’t a general classic-car crowd; it’s a community that tracks individual VINs the way other hobbies track box scores.

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The collection isn’t limited to the usual Mopar muscle-car nameplates, either. Eagle-eyed viewers in the comments pointed out at least one DeSoto parked among the Challengers and ‘Cudas — a reminder that Chrysler’s performance and luxury brands shared factories, parts bins, and showroom floors long before “Mopar” became shorthand for muscle cars specifically. Mecum itself has built a reputation as the largest collector-car auction company in the world, and features like this one are part of how it fills a sale of this scale: walking a camera through a private garage months ahead of an auction date, letting the cars and their owner do the selling before a single lot number gets assigned.

Two Different Mopars, One Shared Family Tree

Swainson’s collection mixes two different branches of Plymouth’s late-’60s performance lineup, and the distinction matters to anyone trying to make sense of it. The Road Runner and GTX shared Chrysler’s mid-size B-body platform but were built for opposite ends of the market: the Road Runner launched in 1968 as a deliberately stripped-down budget muscle car, while the GTX, in production since 1967, was the upscale, better-trimmed performance model built on the related Sport Satellite body. The Road Runner’s low price and cartoon branding made it a runaway seller — well over 80,000 built for 1969 alone — while the pricier GTX never came close to those numbers and was folded into the Road Runner lineup as a trim option after 1971. A real GTX from that final standalone year, let alone one with the rare Hemi option that fewer than 1,000 buyers ordered annually, is a different kind of find than the ‘Cudas and Challengers parked next to it.

The Barracuda and Challenger are a separate story. Both rode on Chrysler’s all-new E-body platform starting in 1970 — a shorter, wider reworking of the existing B-body, styled by John E. Herlitz, that shared no exterior sheet metal between the two cars despite the common underpinnings. The bigger change was under the skin: the E-body’s engine bay was roomier than the A-body platform it replaced, and that extra room is what let Chrysler finally put the 426 Hemi into a Barracuda for retail sale. The ‘Cuda got its 425-horsepower dual-quad Hemi starting in 1970, after years of the engine simply being too large to fit.

The Year Plymouth Took the Six-Barrel Away

1971 pared the ‘Cuda’s engine lineup down. The six-barrel 340 that had powered the limited-run AAR ‘Cuda in 1970 didn’t return for 1971; the standard 340 four-barrel stayed on the options sheet, but the six-barrel small-block was gone for good, along with the AAR package itself. The 426 Hemi hung on for one more year before it, too, was retired — Chrysler built the Hemi ‘Cuda for only two model years, 1970 and 1971, with roughly 114 built across both years combined, making it one of the rarest production muscle cars of the era regardless of which year a given car wears. The GTX’s Hemi option was just as scarce in its own lineup, with fewer than 1,000 built most years, which is part of why a real one commands attention the moment it rolls into a showroom like Swainson’s.

Four Headlights the Barracuda Would Never Wear Again

What 1971 gave back was cosmetic, but it’s the detail collectors point to first: quad headlights, run across the Barracuda’s nose for that single model year only. The Challenger wore four headlights for its entire run from 1970 through 1974 — so for Dodge’s sibling car, the look was never rare. For the Barracuda, it was a one-year appearance that never repeated before Plymouth reworked the car’s face again for 1972. That narrow window is a large part of why 1971 ‘Cudas carry a premium with collectors who care about originality: the car looks different from every other year of E-body Barracuda built, on purpose, for exactly twelve months of production.

It’s a reminder of how much of a muscle car’s collector value comes down to small, dated choices that nobody at the factory thought of as permanent. A grille insert, a lighting pod, an engine option pulled from the order sheet — decisions made for a single model year, usually for cost or emissions reasons rather than any grand design plan, end up defining which cars from an era are easy to find and which ones get hunted for decades. The same logic applies up and down Swainson’s showroom: a 1969 GTX convertible is scarcer than a 1969 GTX hardtop for the same reason a 1971 ‘Cuda looks different from a 1970 — a single model-year decision, made and then abandoned.

Why a Private Collection Like This One Matters

Collections the size of Swainson’s are rare for a reason: they take years of patient buying, usually car by car, often from owners who aren’t actively looking to sell. What the video captures is less a showroom and more an archive — cars that might otherwise have been scattered across different states and different owners, kept together long enough that their individual histories (who ordered them, what they were used for, who restored them) don’t get lost along the way. When pieces of a collection like this do go to auction, as a handful did at Mecum’s record-breaking 2026 Spring Classic, it’s often the first time in years that the broader collector world gets a real look at cars that otherwise live quietly in a private garage, and the first chance for the next owner to pick up a thread of history that would otherwise have gone cold.

Watch the full video above and let us know your thoughts in the comments.