Ringbrothers Turns a Vintage Pontiac Into a 650-Horsepower Showpiece
Ringbrothers reportedly spent more than 5,500 hours building a widened, 650-hp GTO from a 1965 Pontiac, shown at SEMA.
Custom car builder Ringbrothers has unveiled a heavily modified 1965 Pontiac, according to Car and Driver. The car, named Billie, is built on a Pontiac Tempest convertible and is presented as a GTO. Car and Driver reports that it was shown at the SEMA trade show, where the company returned with the project.
Motor1 reports that the build took more than 5,500 hours. The shop widened the body by about five inches, a change that would have required extensive fabrication work to keep the proportions looking right. Both outlets describe the result as producing roughly 650 horsepower.
Car and Driver says the car uses carbon-fiber bodywork, a material chosen to reduce weight compared with the steel panels used on the original car. The powertrain is an LT4 supercharged V-8, a modern General Motors engine that replaces the period-correct powerplant the car would have originally carried.
Both outlets frame the car as a showcase rather than a production vehicle. Neither report provides pricing, sales plans or details about whether the car will be offered to customers.
Background
The Pontiac GTO began in 1964 as an option package for the Tempest, a mid-size car that GM's Pontiac division sold in several body styles. The package quickly became one of the defining American muscle cars, pairing big V-8 power with a relatively light body. Convertibles were part of the original lineup, which is why a Tempest convertible makes a logical starting point for a build like this one.
Restomods, the term used for classic cars updated with modern mechanical parts, have grown into a major part of the custom car market. Owners typically keep the original silhouette and interior character while swapping in newer engines, brakes, suspensions and electronics. The appeal is that the car drives and stops like a contemporary vehicle without losing the look that drew the owner to it in the first place.
SEMA, the Specialty Equipment Market Association, runs an annual trade show in Las Vegas that serves as a major showcase for the aftermarket industry. Builders use it to display concepts, parts and finished vehicles, and many high-end projects debut there because the event draws manufacturers, suppliers and enthusiasts in one place.
The LT4 is a supercharged small-block V-8 from General Motors, a family of engines that has powered the company's performance cars for decades. Fitting a modern engine into a classic chassis usually involves custom mounts, cooling and wiring, and sometimes changes to the frame or driveline. Widening a body adds further complexity because it affects suspension geometry, wheel fitment and the structural relationship between panels. These are the kinds of tasks that can account for the thousands of hours reported for projects of this scale.
Why it matters
Builds like Billie show how far the restomod category has moved beyond simple engine swaps. When a shop can change the width of a classic body, replace much of the car with lightweight composite material and install a modern supercharged engine, the finished machine becomes a different kind of object. It is no longer just a restored car. It is a new vehicle that borrows its identity from the past.
The project also highlights the value that enthusiasts place on craftsmanship. Hours of labor are rarely recovered in dollars when a car is sold, yet the market for exceptional custom builds has remained strong. For the broader industry, showcases at events like SEMA act as a signal of what buyers may want, and they often influence parts makers and smaller shops that follow.
There is a question of audience, too. A car this specialized is aimed at a small group of collectors and show-circuit regulars, not everyday drivers. That limits its direct relevance to most buyers, but it can still shape expectations about what modern performance and classic design can look like together. Even when a build never reaches production, its ideas often filter into mainstream products over time.
What to watch
Whether Ringbrothers or the car's owner plans any further public appearances, such as additional shows or track demonstrations, would show how the project is being used. Any announcement about sales, reproduction parts or a follow-up build would also be worth noting.
Coverage from other outlets may add detail on the car's specifications, including how the widened body was engineered and how the carbon-fiber panels were integrated. Readers should check later reporting for confirmed figures, since current coverage relies on the claims made by the builder and the outlets that covered the reveal.
Viewpoints
Commentary from our columns: three angles on this story.
The Driver's Seat the enthusiast's take
There is something quietly thrilling about a car that looks like it rolled out of a 1960s showroom and then turned out to be a completely different machine underneath. Billie takes the GTO's basic shape, stretches it, and fills it with a supercharged engine that would have seemed like science fiction to the people who first drove these cars. That tension is the whole point.
Enthusiasts will argue about whether the modifications respect the original. Some will love the wider stance and the carbon-fiber skin. Others will miss the steel and the simplicity that made the first GTOs so raw. Both reactions are reasonable, and both say something about why this genre keeps growing.
What stands out most is the patience behind the car. Five thousand hours of work is a commitment that few owners could make alone. For anyone who has ever sketched out their dream classic on a napkin, Billie is a reminder of what a skilled shop can do when given time and a clear vision.
The Engineer how the hardware works
The most interesting question here is how a body widened by five inches holds together. Adding width changes how loads move through the chassis, how the suspension mounts sit, and how the wheels and tires fit inside the arches. Doing that well means reworking geometry, not just stretching panels.
Pairing that with carbon-fiber bodywork shifts the balance further. Composite panels can save weight and be shaped with precision, but they must be bonded and mounted to a structure designed for steel. The joints and load paths become a central engineering challenge rather than an afterthought.
Then there is the powertrain. A supercharged V-8 generates a lot of heat and demands serious cooling, reliable fuel delivery and a driveline capable of handling the torque. Getting an engine of that output to play nicely with a chassis from the 1960s is a technical achievement, and the details are where the real story lives.
The Accountant price, value and running costs
Headline horsepower and striking bodywork are easy to admire, but the numbers that matter to most buyers look different. A build that took more than 5,500 hours carries an enormous labor cost, even if the owner never sees a bill for every hour. Custom projects of this kind rarely recoup their expense at resale.
Running costs are another consideration. Carbon-fiber panels can be expensive to repair after a minor collision, and a supercharged engine with bespoke components may require specialized service. Parts for a one-off widened body are unlikely to be sitting on a shelf at the local dealer.
None of this makes Billie a bad idea. It simply means the car belongs in the category of passion purchase rather than investment. Anyone tempted by a project like this should budget for maintenance and insurance as carefully as they budget for the build itself.