Stealthy Power: The Coolest Classic Sleeper Muscle Cars

2. Plymouth GTX

Plymouth introduced the GTX in 1967 as a luxury option in the Belvedere lineup. They based this model on the same platform as the Coronet, but it was much more luxurious. Also, it had a 375 HP 440 V8 engine as standard. Plymouth wanted the GTX to compete with the luxury cars of the period.

So, they installed almost all the possible creature comforts along with a special trim on the outside to distinguish the GTX from the rest of the model lineup. The GTX was a gentleman’s hot rod with all the options, a nice interior, and exterior details. However, it only had one optional engine choice: the mighty 426 Hemi.

The 440 Magnum was the standard engine, but if you wanted the ultimate Plymouth muscle luxury, you had to go for the Hemi. Due to the fact that it was significantly more expensive than the rest of the Mopar muscle car line up, the GTX was not that popular, so it is rare today.

3. Chevrolet Bel Air 427

The Bel Air once was the top of the line Chevrolet, but in the mid-to-late ’60s, it was an entry-level model in the full-size lineup. Most performance-oriented buyers looked for the Impala SS cars. But those who were in the know bought the Bel Air with the optional 427 V8 under the hood.

The Bel Air 427 was the definition of a sleeper muscle car. It had plain looks, a two-door body with B-pillars and dog dish hubcaps. You could opt for either the 390 or 425 HP rating from the thumping seven liters of American muscle. From the outside, the Bel Air 427 looked like any other Chevrolet. In fact, it had more of a rental car appearance than anything else.

4. Buick Century GS

The Buick Century GS was a colonnade-style intermediate coupe, similar to the Pontiac and Oldsmobile intermediates that featured the characteristic front-end design. The GS was primarily an appearance package that just mimicked the looks and style of previous models. The standard engine was the 150 HP 350 V8.

However, if you optioned for the 455 Stage 1 big block, you could get 270 HP as well as revised brakes and suspension. This version delivered some performance so you could consider it the last true Buick muscle car. However, the number of Century GS Stage 1 cars they produced in 1973 was low at just around 700. But they offered them with a four-speed manual or a three-speed automatic transmission.

5. Pontiac GT 37

Behind the strange name was a regular Tempest with a few performance options and an engine choice from the much more popular GTO model. This meant that buyers who had $3,000 to spend could get a car from 255 HP all the way up to 345 HP. Pontiac advertised the GT-37 as a “GTO lite,” but the car lacked the exterior features like the famous Endura bumper and rear spoiler.

For 1971, they offered the famous 455 V8, but it went in only a handful of cars. Simply, the GT-37 had the performance and the hardware, but it didn’t have the GTO’s appeal and image. And that resulted in bad sales. In two years, Pontiac made only around 2,000 of these misunderstood sleeper muscle cars.

6. Rambler Rebel V8

This one is an interesting early muscle car that was born by chance. Squeezing a 327 V8 engine from the Nash Ambassador into the small, compact and light Rambler body created one seriously fast yet unassuming muscle machine. The 327 V8 delivered 255 HP, which wasn’t that much but in the compact Rambler body, it was enough for 0 to 60 mph time of just seven seconds.

But to make things even more interesting, only the expensive fuel injected Chevrolet Corvette could beat the small Rambler in 1957. However, the powerful engine option raised the price of an affordable Rambler. So, there were just a few buyers ready to pay extra for the privilege of outrunning anything else on the road. And for that reason, Rambler only built 1,500 of them.

7. Chevrolet Laguna 454

Even though it was an upscale model in the early ‘70s Chevelle lineup, the Laguna went unnoticed. And today, it is totally forgotten. But back in the day, Chevrolet tried to make the Laguna desirable by giving it several body styles. They added the 350 V8 as the base engine, although with only 145 HP, and a long list of optional extras.

However, nothing helped so after a few years, they discontinued the Laguna. Interestingly, you could consider the Laguna to be one of the last classic Chevrolet muscle cars. That is because they offered it in a coupe body style for 1974 with the optional 454 V8. Of course, the power level wasn’t high, but the big 454 still produced enough torque to spin the rear wheels.

8. Plymouth Fury GT

Despite being an economy brand for the Chrysler Corporation, Plymouth had a surprisingly large number of muscle cars during the ‘60s and ‘70s, as well as numerous special versions. Their luxury muscle car was the GTX, but in 1970, the Fury GT debuted as the biggest model on offer.

The Fury GT was a two-door coupe version of the Fury sedan. But in a GT guise, it was a full-size muscle car with the perfect combination of stealth looks and power. Under the hood was the famous 440 V8. It came with a three-carburetor setup and 375 HP on tap.

Buyers could choose between the 727 Torqueflite automatic and the four-speed manual. However, if you wanted a better performance, you would choose the manual. But despite the power and looks, the Fury GT wasn’t a big performer since it was still a heavy car.

9. Buick Gran Sport 455

The Buick GS 455 is special and interesting in muscle car mythology. Like all other GM muscle cars, they limited the Buick Gran Sport to 400 CID. But, in 1970 when GM lifted its ban on engine displacement, Buick decided to introduce a strong model they simple named the Gran Sport 455. This car featured the famous 455 V8 they rated at 360 HP that could launch this big, heavy car to 60 MPH in just around 5.5 seconds.

This was lightning fast in 1970 and its speed is still respectable today. The power output wasn’t that far from the 1969 GS 400, but the torque figures were significantly higher. The mighty 455 engine delivered over 500 lb-ft of torque, making it one of the strongest muscle engines of all time.

This characteristic launched Buick into the front row of the most powerful models of the period. Since it was a Buick, they equipped the GS 455 with decent standard equipment and a long list of optional extras. Imagine all that in a modern-day package. You would get a super-luxurious modern muscle car that offers a pleasant, yet blisteringly fast ride.

10. Ford Mustang 289 HiPo

From the outside, the Mustang 289 HiPo or High Power looked like any other Mustang. But under the hood, this 289 HiPo hid one of the best small blocks of the muscle car era. The K-Code had a 289 V8, but with a sporty tune and 271 HP, it more than enough for the decent performance Mustang fans demanded.

With the optional GT package that included a stiffer suspension, better equipment and lots of exterior details, the 289 HiPo was the choice of real car fans. Ford introduced it in 1965 and made it available until 1967. Most notably, the 289 HiPo was the first Mustang that ran as well as it looked, especially if you ordered it in the gorgeous Fastback body style.

11. Oldsmobile Toronado GT

The GT was a special package for Oldsmobile’s personal luxury cruiser. It was available for a few short years, ending in 1970. From the outside, the Toronado GT looked like an ordinary Oldsmobile powered by the same 455 engine, but the devil was in the details.

The GT package upped the power to a magical 400 HP, added various suspension bits, bigger and stronger front disc brakes and better interior equipment. The GT was a rare option, so people seldom decided to order their Oldsmobiles with this package. And that is exactly why it is so desirable today.

12. Chevrolet Camaro ZL1

The Camaro ZL-1 was the same as a regular 1969 Camaro on the outside, but it was so fast, it was barely street legal. It had a high revving, 7.0-liter V8 producing around 550 HP in mild tune. Chevrolet produced around 200 of those engines. While most of them went to the Can-Am racing teams, they installed 69 ZL-1s in those C.O.P.O Camaros, selling them to drag racing teams.

13. Pontiac Catalina 2+2

In the mid-60s, the Pontiac GTO was the car to have since it was at the forefront of the exciting new muscle car movement. With its performance, powerful engine and great Pontiac styling, the GTO was the perfect car for the moment. But it wasn’t the only stellar performance machine coming from Pontiac. In 1965, there was another pure muscle car icon in the form of the Catalina 2+2.

Since the Catalina was a full-size model, it was eligible for engines over 400 CID, according to the GM rules of the time. This meant the Catalina 2+2 came with the famous 421 V8. But you could get the Tri-Power intake system, which was the same as in the GTO. It could boost your car’s power up to 376 HP. Also, the buyers could order limited-slip differentials, heavy duty steering and brakes, and a lot more.

All that made the Catalina 2+2 well appointed, but unfortunately, expensive too. The top of the line 2+2 cost over $4,000, which was a hefty sum and much more than similarly-equipped GTO, for example. However, Pontiac produced around 11,000 of these fine machines in 1965, but only around 200 are convertibles.

14. Chevrolet Impala SS

The legendary SS or Super Sport package has its place in muscle car history as an important model that promoted performance to the public. This was one of the first high-performance automobiles that were relatively affordable yet fast. Everything started when Chevrolet decided to transform their 409 truck engine to use for passenger cars.

They found out that the unit was powerful and could outrun all other cars on the road. Just by mild modifications to the engine, it could produce up to 409 HP, which was enough to propel the Impala from a standstill to 60 mph in six seconds flat.

Amazingly, at the time, that was Corvette territory. So, as a mid-year introduction, Chevrolet presented the SS package featuring bucket seats, sports trim and other details. Also, it came with the 348 V8 engine delivering 350 HP. However, the most interesting option was the 409 V8 producing up to 409 HP if you optioned for the dual quad intake system.

15. Ford 7-Litre

Ford introduced a new full-size model for 1966 they called the 7-Litre. The “7” stood for displacement and “Litre” spelling gave more charm to the otherwise ordinary Galaxie. Under the hood was the 428 V8 with a respectable 345 HP that delivered a convincing performance.

However, the 7-Litre’s equipment was also interesting since Ford put everything they had into this car. The buyers could get A/C and bucket seats were standard. There was also a heavy-duty suspension, power everything, a choice of special colors and of course, those 7-Litre badges on the sides that helped identify this model. This was a one year only model and in 1967, the 428 was back, but only as an option on the Galaxie and not as q standalone model.

16. Dodge Coronet 426 Hemi

The Chrysler Corporation introduced its legendary 426 Hemi engine for 1966 as an option on certain Plymouth and Dodge models. The iconic power plant was an option on the Dodge Coronet as well, and technically, drivers could get it with any body style. However, most buyers associated Hemi power with two-door coupes or convertibles, so they didn’t realize they could have a Hemi in a sedan or even in wagon form.

And that is why only a few people bought the Coronet Deluxe Hemi four-door in 1966, getting the ultimate sleeper muscle car sedan. With advertised 425 HP under your right foot, the Coronet Hemi four-door was arguably the fastest production sedan in America and the ultimate muscle car with four doors.

These are the cars with stealthy power. They are the coolest classic sleeper muscle cars you can drive today. While some are rare, others are easy to find. Either way, all of these cars are great at hiding their power until you press down on the gas pedal.