The Big-Block Barracuda Most People Forget: 1967 Formula S

Plymouth had a problem in 1967: everybody suddenly wanted a pony car, and the original Barracuda still looked like what it was, a Valiant wearing a fastback window. So Plymouth started over on the sheetmetal, and buried in the options list was a big-block that turned a reworked economy car into something that could hang with the muscle crowd. Most people who spot one today assume it is the small-block version. Read on for the Barracuda most people forget existed.

Classic 1967 Plymouth Barracuda Formula S parked under a cloudy sky.

Plymouth had a problem in 1967, and it was a problem of its own making. Everybody suddenly wanted a pony car, Plymouth had technically gotten to the market first, and the car it had gotten there with still looked like exactly what it was underneath, which was a Valiant wearing an enormous fastback rear window. So Plymouth tore up the sheetmetal and started over. Buried deep in the options list of the car that resulted was a package that turned a reworked economy compact into something that could genuinely run with the muscle car crowd. Most people who spot one of these at a show assume it is the small-block version, and most of the time they are right. The ones that are not are a very different story.

The Pony Car That Beat the Mustang to Market

The detail that gets forgotten is that the Barracuda actually beat the Mustang into dealerships, arriving on the first of April in 1964, roughly two weeks before Ford’s launch. Plymouth simply did not have the product to capitalize. That first car was a Valiant with a huge wraparound backlight and not much else to distinguish it, and while the glass was genuinely striking, the car underneath was economy transportation. Ford, meanwhile, had built a purpose-designed body on borrowed underpinnings and marketed it relentlessly. Plymouth was first and lost anyway, which is exactly the sort of lesson that concentrates a product planner’s attention when the redesign budget finally arrives.

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A Real Redesign, Not Just a Facelift

The second-generation Barracuda, built from 1967 through 1969, was still Valiant-based underneath but received a genuine ground-up restyle, and for the first time buyers could choose between fastback, notchback hardtop, and convertible body styles rather than being stuck with a single silhouette. The proportions improved dramatically, the greenhouse looked deliberate rather than grafted on, and the wider engine bay opened possibilities the first-generation car never had. Total 1967 Barracuda output came in just over 62,000 units across all three bodies, with the convertible by far the scarcest of the three, which matters when you start looking at how thin the desirable configurations get from there.

What the Formula S Package Actually Did

The Formula S package had been introduced back in 1965 and carried over into the new body, and it was a suspension package before it was anything else. It brought heavy-duty torsion bars up front, additional leaves in the rear springs, uprated shock absorbers at all four corners, a factory front anti-roll bar, wide-oval Red Streak tires, and Formula S badging on the fenders. That is a meaningful list for the period, and it is why these cars developed a reputation among people who actually drove them as being genuinely fun to throw into a corner rather than merely quick in a straight line. Chrysler’s torsion bar front suspension was one of the better setups in Detroit, and the Formula S made proper use of it.

The Small-Blocks Most Cars Left With

Most 1967 Barracudas left the factory with a 273-cubic-inch small-block, available either as a 180-horsepower two-barrel or as the 235-horsepower Commando four-barrel version with a higher compression ratio and a hotter camshaft. The 273 Commando in a Formula S is a genuinely good combination, light over the nose and happy to rev, and it is the configuration most surviving cars carry. For 1968 Plymouth would add the excellent 340-cubic-inch small-block, which many people consider the sweet spot of the entire second-generation run, but for 1967 the 273 was the standard-issue performance answer and the big-block was the exception.

The 383 Nobody Expects to Find

That exception is the 383-cubic-inch big-block, rated at 280 horsepower in Barracuda form. The number is lower than the same engine’s rating in a Coronet, and the reason is packaging: the Barracuda’s engine bay was tight enough that Chrysler had to use more restrictive exhaust manifolds to clear the shock towers, which cost the engine real output. It was a seldom-ordered option that turned a compact-based pony car into something that could genuinely surprise people at a stoplight, and Chrysler built noticeably fewer big-block cars than small-block ones that year, with the convertible configuration scarcest of all.

The Compromises That Came With the Big Engine

The 383 came with compromises that tell you a great deal about how tight the fit really was. Cars ordered with the big-block could not be had with power steering or air conditioning, because there was simply nowhere to put the pumps and compressors once the engine was in place. That is not a trim-level decision, it is a physical one, and it meant a 383 Formula S was a heavy-steering car that got hot in traffic. Buyers who wanted comfort took the 273 and buyers who wanted the engine accepted the consequences, which is a large part of why so few of the big-block cars were ordered in the first place.

Why the Numbers Are So Small

Put those factors together and the rarity makes sense. The Formula S was already a minority option, the 383 was a minority within that, the deletions made it a hard sell to anyone who was not committed, and the cars that did sell were bought by people who intended to use them hard. Attrition over five decades did the rest. A documented big-block Formula S is genuinely uncommon, and it is one of those cars where the auction description matters enormously, because dropping a 383 into a small-block car is a well-trodden path and the numbers on the block are the only thing standing between a real one and a very good imitation.

What to Check Before Buying One

If one turns up, verify the fender tag and the block casting and stamping codes before anything else, and look for the absence of power steering and air conditioning as a supporting clue rather than proof on its own. Structurally, Chrysler A-body cars rust in predictable places: the front torsion bar crossmember and its mounting points, the floor pans, the trunk floor and the rear frame rails, the lower quarters, and the cowl vents that dump water into the footwells when the drains clog. Reproduction parts support for the 1967 to 1969 Barracuda is thinner than for a Mustang or Camaro of the same era, so a straight, complete car is worth paying a premium for. Share your thoughts in the comments below.

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