Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car - story fullscreen Fullscreen

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car

The Kellison J6 Panther was, essentially, a Corvette-based kit that turned the American icon into a ground-bound fighter plane

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The Chevrolet Corvette is one of the most iconic American sports cars. And while there’s hardly any Corvette worth missing out on, the American icon also proved to be a great basis for other high-performance machines. One of the greatest examples of that is the Kellison J6 Panther, which was the creation of former aircraft engineer, Jim Kellison, who in 1958, founded Kellison Auto Engineering company and aimed to build an even faster version of the Chevrolet Corvette.

The J6 Panther was the pinnacle of the Kellison J series

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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To this day, the Chevy Corvette is a great basis for projects
But in the early 1960s, the Kellison J6 Panther was the ultimate Corvette-based kit car

The Kellison J6 Panther was part of the J series. There was the J1, J2, J3, J4, J5, and J6, all of which had their own distinctive traits, most notably the size, bodywork, and various design elements such as the headlight and taillight design. Unlike most of Kellison’s J series, the J6 Panther was available only as a coupe.

The J6 also returned to a more streamlined design, compared to the J5, which was a version of the J4 with quad-headlights that somewhat resembled the Baldwin Motion Manta-Ray Chevrolet Corvette, of which only one is said to remain. The Kellison J6 Panther was based on the 1953 to 1962 C1 Corvette chassis with its respectable drivetrain components. This meant a live rear axle and drum brakes front and rear. With that being said, at least one Kellison J6 Panther body was transplanted onto a 1968 C3 Corvette chassis (C2 and C3 have the same 98-inch wheelbase).

One of the very first fiberglass kit cars

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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The last of the J series
The J6 Panther was preceeded by 5 other versions, all of which relatively similar, but with different body styles and dimensions

The Kellison J series were kit cars, intended for the C1, C2, and apparently, the C3 Corvette, which technically made them re-bodied Corvettes. Like the Corvette, all bodies were made out of fiberglass. While the Chevrolet Corvette C1 was the first sports car to feature a fiberglass-made body, Jim Kellison decided to improve upon the design. The Kellison J series was the first kit car body made entirely out of fiberglass, preceded only by the 1949 Glasspar G2.

The J6 Panther was intended to be more comfortable than the rest

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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According to Kellison classic cars, each of the J series kit cars was designed in stages. The idea was to design the individual bodies to fit on different frames (C1 or C2 chassis). Then they would be modified, depending on different requirements, for more legroom and headroom. At 167 inches (4,241.8 mm), the J6 Panther was the second-longest of the J series, surpassed only by the J5’s 176 inches (4,471.4 mm) length.

Kellison cars quotes a wheelbase of 100 to 104 inches (2,540 to 2,641.6 mm), which is matched only by the J4, of which the J6 Panther was a derivative. The J6 also measured 66 inches (1,676.4 mm) in width and just 39 inches (990.6 mm) in height, which meant it was lower than the original, 1964 Ford GT40. Other distinctive features were the more sloped rear end and trunk lid, more angular grille, and the return to a single headlight design.

Inspired by aircraft

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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A fiberglass body inspired by aircraft
Its creator, Air Force engineer, James Kellison, wanted to make the Corvette as "slippery" as possible

Former air force engineer, James Kellison, began work on his fiberglass body in 1957, at Vacaville, California, in a small garage near his home. The first body was introduced in 1958 and not long after, in 1961, production moved to Folson, California. While all J series kit cars were meant to be as “slippery” as possible, the J6 Panther was the final evolution and was meant for all-out speed. While there aren’t exact figures, the drag coefficient of the J6 Panther is believed to have been a great improvement over the C2 Corvette’s figure of 0.44, despite the raised roofline, compared to earlier J series models.

Surprisingly mass-produced

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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The most mass-produced of the J series
Over 500 of the J6 Panther kits are said to have been sold

While certainly not a common sight on the road, the Kellison J6 Panther was the most produced kit of the whole series. By 1964, over 500 units of the J6 Panther kit were sold. The only kit to come close to that number was the Astra X-300GT, which was another J4 variant from the mid-1960s, sold under the Astra name. Between 350 and 400 examples of the J5. For comparison, production of the J4 ended with 300 coupes and around 25 roadsters. Around 15 coupes and 60 roadsters of the J3 kit were sold while very few of the J1 and J2 kits are believed to be made.

What engine powered the Kellison J6 Panther?

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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Nowadays, it’s hard to find one with the original engine
While most of the J6 Panthers are believed to have come with a 327 small-block, various examples have been restored with different engines

It’s very difficult to pinpoint what engines powered the Kellison J series since many of them have been resto-modded over time and had the original powerplant swapped for a more modern one. As it was, essentially, a re-bodied Corvette, the 327 cubic-inch (5.4-liter) small-block would have been standard. Transmission-wise, it was either a Muncie M20 series, four-speed manual, or a TH400, three-speed automatic.

Some restored examples have been reported to have a 306 cubic-inch small-block V-8, a 350 cubic-inch GM crate engine, or a 396 cubic-inch engine. And those are just the ones we know about. At any rate, the Kellison J6 Panther would have been propelled by at least 300 horsepower, which given the dry weight of 1,840 pounds (835 kg), would have translated to some impressive performance.

A kit car that’s also a sought-after classic?

Kellison J6 Panther - The True Story Behind This Forgotten American Muscle Car
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The last of the J series
The J6 Panther was preceeded by 5 other versions, all of which relatively similar, but with different body styles and dimensions

The notion of a kit car that, potentially, has a collectible status may sound absurd, but the Kellison J6 Panther is one of the very few to achieve that. While being based on a Corvette may have something to do with that, one of the very few well-preserved J series was sold two years ago, on Bring a Trailer, for just under $65,000.

Dim Angelov
Dim Angelov
Born in 1992, I come from a family of motoring enthusiasts. My passion for cars was awoken at the age of six, when I saw a Lamborghini Diablo SV in a magazine. After high school I earned a master’s degree in marketing and a Master of Arts in Media and Communications. Over the years, I’ve practiced and become skilled in precision driving and to date have test driven more than 250 cars across the globe. Over the years, I’ve picked up basic mechanical knowledge and have even taken part in the restoration of a 1964 Jaguar E-Type and an Alfa Romeo Giulia Sprint. Lately, I’ve taken a fancy to automotive photography, and while modern cars are my primary passion, I also have a love for Asian Martial Arts, swimming, war history, craft beer, historical weapons, and car restoration. In time, I plan my own classic car restoration and hope to earn my racing certificate, after which I expect to establish my own racing team.  Read full bio
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