One of the rarest and most forgotten muscle cars is the Pontiac GT-37. It wasn’t a model of its own but an option package on the 1970 and 1971 Tempest. The inspiration for this model came from Plymouth. In 1968, Plymouth introduced the Roadrunner, a budget-friendly, bare-bones muscle car with wild graphics and few options. Pontiac intended the vehicle to be for younger buyers with limited budgets yet a need for performance. The Roadrunner proved to be a strong seller. Soon, all car companies started thinking about inexpensive models to attract younger customers. But for some reason, Pontiac waited until 1970 to introduce such a model in the form of the GT-37.
Behind this strange name was a regular Tempest with a few more performance options and an engine from the more popular GTO model. This meant buyers who had $3,000 to spend could get a car from 255 HP all the way to 345 HP. Pontiac advertised the GT-37 as the “GTO Lite,” but the car lacked exterior features like the famous Endura bumper and rear spoiler. For 1971, they offered the famous 455 V8, but it only went in a handful of cars. Simply put, the GT-37 had the performance and the hardware but it lacked the GTO’s appeal, resulting in bad sales. In two years, Pontiac made only around 2,000 of these misunderstood muscle cars. Today, the GT-37 is a rare sight.
Back in the mid-1960s, AMC was famous for its lineup of economy cars and small sedans. This was before the AMC Javelin and AMX entered the mainstream muscle car class. However, AMC company management wanted an exciting, sporty car, so they turned to their Marlin model. As a result, the Marlin was a mid-size fastback with a design suggesting it was fast and powerful. The truth was the car only delivered mediocre performance. But for the 1967 model year, AMC decided to introduce a 343 V8 version of the Marlin with 280 HP on tap.
Despite the fact it wasn’t a lot, it was still enough to provide the Marlin with decent performance and driving dynamics. Today, 343 V8-powered Marlins are rare, but there are even rarer versions. Some had a factory-tuned 343 V8 engine that produced 320 HP, giving the Marlin real power. While it’s unclear how many of those special-order cars they made today, they are nearly impossible to find.
In the early ’60s, Studebaker management decided to invest in a luxury coupe to fight their poor sales. They thought a new, fancy upscale model would attract more customers to Studebaker. In 1962, they presented the sleek, modern-looking Avanti. The innovative design, construction, and technology were impressive, and the car received praise from the motoring press. But the base version wasn’t powerful, so Studebaker introduced its supercharged R2 option delivering 289 HP. The R2 version didn’t come with an automatic transmission or air conditioning. In fact, it only came with a close-ratio manual gearbox. However, they included some performance upgrades, turning the Avanti into a fast machine.
Incredibly, the R2 broke 28 world speed records by achieving top speeds of 170 mph, a big deal in 1963. The R2 could sprint from 0 to 60 mph in just 7.3 seconds. Unfortunately, Studebaker had problems with production, so the Avanti was limited in availability, affecting its popularity. Sadly, by 1964 they discontinued this model. Today, most car enthusiasts recognize the Avanti R2 as one of the coolest ’60s cars as well as an early luxury muscle car. During its short production run, Studebaker produced just over 4,600 Avantis and only a handful were R2s.
In 1971, dark clouds were on the horizon for muscle car enthusiasts. Tightening government regulations, high insurance rates, and environmental standards attacked the segment. Manufacturers understood they had to act fast to save the market. So the first thing they did was introduce economy versions of their popular muscle cars. They gave their cars smaller engines but interesting designs to maintain appearance and popularity. One of those models is the 1971 Chevelle “Heavy Chevy.”
It was an interesting one-year-only muscle car positioned below the Chevelle SS lineup. The Heavy Chevy came with a 200 HP 307 CID V8 engine, and you could also opt for a 245 HP 350 CID V8 engine. The most powerful version was the 300 HP 402 CID V8. If you wanted a top-of-the-line 454 big-block V8, you had to go the SS route. Although the Heavy Chevy was a popular model and they built over 6,500 of them in one year, it’s quite rare today.
Back in the late ’70s, the American performance car segment was a shadow of its former glory. Tight ecological and safety standards killed those high compression engines and ruined performance. Although there were a few surviving models, “performance” was just a word people used in magazine ads. But in 1977, everything changed when Pontiac introduced the Can-Am. The Can-Am was a one-year-only model and the last real muscle car. It had big-block power packed into its unique body style. Under the hood scoop sourced from the Firebird Trans Am, a big 455 engine was delivering 200 HP. That was more than any other muscle car on the market at the moment.
The Can-Am package consisted of special rear window louvers, rear spoilers, and optional extras. Pontiac introduced the Can-Am in early 1977 and the market responded well. Pontiac received between 5,000 and 10,000 reservations but only sold 1,377 of them. The problem was that the outside contractor that assembled the Can-Am suffered equipment failure. They had to wait three months for the new equipment, but Pontiac couldn’t wait, so they canceled all orders. This killed the Can-Am, and they didn’t offer this model again until 1978.
They conceived the Mercury Cougar as a luxury pony car, building it on a stretched Mustang platform. This meant all the engines they installed in the Mustang could easily fit into the Cougar as well.
In 1969, Ford introduced the Boss 302, and Mercury got its own version too. They called it the Cougar Boss 302. Strangely, Ford didn’t widely advertise this highly-capable pony car, so it remained obscure. Mercury produced just 169 of them, and it’s a mystery how many have survived to this day.
The biggest news for 1969 was the introduction of the Barracuda 440 V8. It was a monster pony car with the biggest engine ever installed under the hood of a car in that segment. The Barracuda 440 produced 375 HP and a massive 480 lb-ft of torque. This made it fast but also hard to launch due to loads of wheel spin.
Due to the engine’s tight fit, there wasn’t enough space for a power steering pump. That meant Barracuda 440 owners had to use their muscles to turn this compact but overly powerful car. Plymouth only made a handful of these models, which makes them very rare today.