Ringbrothers Invests 5,500 Hours to Transform a 1965 Pontiac GTO Convertible into a 650‑HP Showpiece
At SEMA, Ringbrothers unveils “Billie,” a heavily reworked 1965 Pontiac GTO Convertible that began life as a Tempest and now boasts 650 horsepower.
Trend: Classic muscle cars are being reimagined with modern performance and lightweight materials.
From Tempest to GTO
Ringbrothers has taken a 1965 Pontiac Tempest Convertible and rebuilt it into a 1965 Pontiac GTO Convertible, affectionately called “Billie.” The project involved widening the body by five inches and reshaping front fenders, rocker panels, and rear quarters to keep the proportions of the original GTO.
Labor of Love
The shop logged more than 5,500 hours on the build. Co‑founder Jim Ring explained, “The challenge was widening the body five inches without losing the proportions that make a ‘65 GTO so recognizable. We spent countless hours massaging the factory lines, reshaping the fenders, and refining how every panel transitions into the next. There’s a massive amount of fabrication hidden beneath the subtle touches in the design. The goal was to make those changes feel completely natural and organic, as if Pontiac had built it this way.”
Carbon‑Fiber and Custom Bodywork
Carbon fiber is used for the hood with an enlarged scoop and functional vents, front wheel tubs, lower front valance, and rear diffuser. The car also features custom bumpers, redesigned headlight surrounds, and a one‑piece aluminum taillight panel, all finished in a custom Billie Goat Blue paint with polished chrome accents and black detailing.
Powertrain
Under the hood sits a supercharged 6.2‑liter LT4 V8 sourced from Wegner Motorsports. The LT4, also found in GM models such as the Cadillac CT5‑V Blackwing, produces 650 horsepower and 650 pound‑feet of torque. Power is sent through a Bowler Performance 10‑speed automatic transmission.
Performance Upgrades
The exhaust system uses Flowmaster components, while the suspension is handled by Fox RS SV coilovers and a Fast Track Stage III chassis. Braking is provided by Brembo units with six‑piston calipers at both front and rear. The car rides on staggered 19‑ and 20‑inch HRE G‑code wheels shod with Michelin Pilot Sport Cup 2 tires.
Interior Refresh
Inside, the dashboard has been moved four inches forward and two inches lower. The cabin features custom aluminum trim, Dakota Digital gauges, vintage‑style climate controls, and an auto‑dimming rear‑view mirror. A restored factory radio now includes Bluetooth connectivity, and a “Raised by Ringbrothers” plaque is mounted on the dash.
Billie demonstrates how a classic silhouette can be married to modern engineering without sacrificing its iconic identity.
