The Chevrolet Corvette C3, spanning from 1968 to 1982, represents a pivotal era for this legendary American sports car. Emerging after the initial roadster design and the sleek C2 generation, the C3 Corvette truly cemented its place as an icon. This generation boldly embraced a muscular, aggressive stance, a departure from the more reserved European sports car aesthetics of the time. With its available T-tops, potent big-block engines reaching upwards of 500 horsepower, and a fiberglass body endorsed by astronauts, the Corvette C3 became a loud and proud symbol of American automotive prowess, even amidst the looming oil crisis.
And it was precisely this unapologetic character that resonated deeply with enthusiasts.
However, for many owners, the true performance potential of their Corvette C3 remained largely untapped. Many seemed content with its striking looks and iconic status, often making only minor modifications, sometimes opting for questionable wheel choices or excessive chrome, rather than exploring its inherent capabilities.
For a long time, the ideal Corvette C3 in my mind was a well-maintained, mostly stock example, perfect for weekend cruises and occasional track days. That perspective shifted dramatically the moment I encountered “Rambo,” Garret Randall’s formidable 1970 LT-1 Corvette C3, a machine meticulously crafted for autocross domination.
Rambo: A Corvette C3 Reborn for Performance
The origins of “Rambo,” this exceptional Corvette C3, are somewhat shrouded in mystery. After spending its early years as a cherished road car in the Bay Area, its original owners decided in the late 1980s to transform it into a dedicated race car, recognizing its latent performance DNA. When Cris Gonzalez of JCG Restorations & Customs, based in Southern California, acquired the vehicle, it had already been flared and seen track use. While not abused, this numbers-matching Corvette C3 was undeniably in need of significant restoration and a focused direction.
As JCG Restorations & Customs flourished, client projects took priority, and the Corvette C3 sat waiting. This changed when Garrett Randall, an autocross enthusiast, brought his El Camino to Cris seeking inspiration for his own build. Garrett discovered everything he was looking for, and more, in the dormant Corvette C3. A new automotive chapter was about to begin.
Garrett made the decision to part ways with his El Camino and wholeheartedly pursue his vision for the Corvette C3. He purchased “Rambo” from Cris and commissioned JCG Restorations & Customs to undertake a comprehensive build, realizing the full potential Cris had always envisioned, starting literally from the ground up.
Fiberglass Finesse and Performance Engineering
The stance and flared fenders of “Rambo” appear custom-tailored around its massive wheels and tires, and that’s precisely the case. It rolls on imposing 18×11.5-inch front and 18×12.5-inch rear Forgeline GA3R wheels, wrapped in sticky 315- and 335-width BFGoodrich g-Force Rival S tires. After removing the existing flares, Cris meticulously hand-fabricated new fenders at each corner. This process involved shaping fiberglass over temporary aluminum sheet metal and a wire framework, ensuring a perfect fit and aggressive aesthetic for this performance-oriented Corvette C3.
The Corvette C3 was ahead of its time, adopting independent rear suspension in 1963. However, modern upgrades can significantly enhance its performance. The original leaf spring rear suspension was replaced with a coilover setup using a Van Steel conversion kit. Cris and Garrett further refined the system with JRi coilovers at all four corners. The front utilizes 600 lb/in springs, while the rear surprisingly employs softer 90 lb/in springs. A custom JCG sway bar was designed for the front, but remarkably, the rear sway bar was omitted. This deliberate choice aims to maximize rear-end squat, leveraging the Corvette C3‘s inherently light rear, while maintaining a planted and level front end, crucial for optimal autocross handling.
While the Corvette C3‘s original big-block ZL1 engine was undeniably potent, unofficially producing well over its rated 430 horsepower, the modern LS engine platform offers compelling advantages. The LS platform excels in terms of cost-effectiveness, packaging efficiency, weight reduction, reliability, technological advancements, and extensive aftermarket support. Garrett and Cris made the bold decision to part ways with the numbers-matching engine and transmission. They entrusted James Mullenix of Mullenix Racing Engines to build a custom LS6 engine and Tremec T-56 transmission tailored specifically for this Corvette C3 project, ensuring modern performance and reliability.
Supporting modifications are functionally focused, including essential enhancements for a serious track car. These include a Kurt Urban LS Vapor Vent system, a critical Moroso oil accumulator for sustained high-G maneuvers, and a custom baffled aluminum fuel cell. After over two and a half years of demanding 530 whp performance, this meticulously engineered Corvette C3 continues to perform flawlessly.
Blending Classic Style with Modern Innovation Inside
The interior of “Rambo” further emphasizes the harmonious blend of classic and contemporary. AutoMeter Sport-Comp black/aluminum gauges seamlessly integrate into the original instrument panel, providing Garrett with crucial performance data more commonly found in race cars. The factory tape deck and speakers are retained, along with the passenger seat, preserving some of the Corvette C3‘s original character. However, performance takes precedence with a Sparco suede steering wheel and Hurst shifter for enhanced control. Driver safety is paramount, with a Kirkey aluminum racing seat, RCi harnesses, and a custom four-point roll bar providing secure and essential protection.
Subtle yet impactful exterior modifications contribute to the car’s signature appearance. The original side-exit exhaust pipes are gone, replaced by custom rocker panels that, combined with the unique Dodge F8 Green paint, lend a refined aesthetic to this Corvette C3. Custom vents integrated into the factory fiberglass hood subtly hint at the performance lurking beneath. The aggressively cropped rear bumper, custom aluminum diffuser, center-exit Borla dual exhaust system, and the personalized license plate unequivocally declare this Corvette C3 as a purpose-built corner-carving machine.
Conquering the Road and the Autocross Course
Upon completion, Garrett quickly realized that “Rambo” was a machine that surpassed his driving capabilities. However, in just over a year of competing in events like NMCA autocross competitions, he has rapidly progressed, closing a four-second gap to event leaders down to under one second. This remarkable improvement highlights both Garrett’s dedication and the exceptional performance potential engineered into this Corvette C3.
Garrett and “Rambo’s” ongoing mission is to continue pushing their limits in autocross competition and to relish weekend drives, whether cruising around town or tackling winding roads. “It’s not going to get much crazier,” Garrett affirms, confident in the near-perfect state of his Corvette C3.
“It’s pretty much close to perfect just the way it is.”
We wholeheartedly agree.
