Think about the golden age of American muscle and you probably picture cars from the tail end of the 1960s that shouted loud and proud about how fast they could go. Cars like the Chevrolet Chevelle Super Sport, Pontiac GTO Judge, and Plymouth Superbird.

But the sneakiest stoplight drag racers wanted their cars to look as low-key as possible, just as the original muscle cars looked in the early 1960s before the car companies started to make them stand out.

We’ve selected 10 of the stealthiest 1960s muscle cars – machines that don’t make the obvious muscle car lists and you wouldn’t think twice about taking on. But doing so might be a big mistake because you won’t believe how fast these stealthy old timers can go.

Related: 1970 Dodge Charger R/T In Sublime Green Makes Us Wish We Had $90K To Spend On It

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1. 1966 Chevy Biscayne 427
Engine: 427cu in (7.0-liter) V8
Power/torque: 425 hp/460 lb ft
Zero to 60mph: 5.7 sec
Qtr mile: 14.0 sec @ 102mph

Chevy’s 1961-65 409-cube Super Sport Impalas were among the very earliest 1960s muscle cars and achieved the magical one horsepower per cubic inch in their hottest form.

But we reckon their younger brothers are even stealthier. I mean, who’d look at this lowly Biscayne sedan with its dog-dish hubcaps, minimal chrome, bench seat interior, and guess there’s actually a 425 hp solid-lifter big block hiding under the plain black paint?

Credit: Mecum

2. 1970 Buick GS 455 Stage 1
Engine: 455cu in (7.5-liter) V8
Power/torque: 360 hp/510 lb ft
Zero to 60mph: 6.5 sec
Qtr mile: 13.8 sec @ 101mph

The Skylark GS was Buick’s low-key take on the GM A-body component set that also gave us the much more flamboyant Pontiac GTO and Chevrolet Chevelle SS. The new-for-1970 455 engine made 350 hp, or 360 hp in Stage 1 form with its hotter cam, larger valves, and high compression ratio.

That might not sound much when rivals were putting out 400 ponies or more, but check out the torque: a massive 510 lb ft made this one seriously quick muscle car.

Credit: Mecum

3. 1963 Pontiac Catalina 421
Engine: 421cu in (6.9-liter) V8
Power/torque: 405 hp/425 lb ft
Zero to 60mph: 5.4 sec
Qtr mile: 13.9 sec @ 107mph

Long before Pontiac’s GTO had supposedly invented the muscle car, the company was building hot cars like the 421-powered Catalina and Grand Prix for drag racing and stock car competition, some of which found their way to the street.

The dual-carb 421 was rated at 405 hp, and you could maximize that by selecting options like aluminum body panels and later, a “Swiss cheese” chassis that was drilled with dozens of holes to save weight. There was even an aluminum exhaust manifold option, though that was best saved for sanctioned drag racing events for obvious reasons…

Credit: RM Sotheby’s

4. 1969 Chevrolet Camaro ZL1
Engine: 427cu in (7.0-liter) V8
Power/torque: 430 hp/450 lb ft
Zero to 60mph: 5.3 sec
Qtr mile: 13.16 sec @ 110mph

We’ve stayed away from pony cars in this list because they were exactly the kind of machines you’d expect to be packing some serious under-hood hardware. But even if you did notice the cowl-induction reverse scoop on the otherwise totally plain Camaro ZL1, there’s no way you’d have guessed it was optioned with a very special 427cu inch big block V8 that more than doubled the price of the car.

Chevy built 69 of these Camaros to homologate its NHRA quarter mile racers, each rated at 430 hp, but probably making more than 500.

Credit: Mecum

5. 1968 Dodge Dart 440
Engine: 440 cu in (7.2-liter) V8
Power/torque: 375 hp/480 lb ft
Zero to 60mph: 5.0 sec
Qtr mile: 13.3 sec @ 107mph

Dodge’s sensible little Dart was unlikely to arouse much suspicion if it pulled up in the next lane, even with the twin stripes wrapped around its tail. It was probably just a 275 hp 340, and you reckon you could probably take it.

And you’d be wrong. This car is one of 650 Darts stuffed full of 440cu in V8 and let loose on the street. The big motor took up so much space there wasn’t room for power steering hardware or a brake servo, so the Dart 440 came equipped with manual steering and unassisted drum brakes at each corner. Terrifying.

Credit: Mecum

6. 1967 Mercury Comet 427
Engine: 427 cu in (7.0-liter) V8
Power/torque: 425 hp/480 lb ft
Zero to 60mph: 6.0 sec
Qtr mile: 14.3 sec @ 102mph

The Comet was Mercury’s equivalent of the Ford Fairlane, and in 1967 Mercury made Ford’s mighty 427-cu inch V8 available in any Comet from the flashy Cyclone hardtop to the most basic pillared 202 sedan.

The 427 came in 410 hp single-carb form, or with twin Holleys and 425 hp; both were equipped with a four-speed manual. But other than the tiny 427 badge on the front fender, there was nothing to suggest what was hiding under the hood.

Credit: Mecum

7. 1966 Plymouth Belvedere Hemi
Engine: 426 cu in (7.0-liter) V8
Power/torque: 425 hp/490 lb ft
Zero to 60mph: 5.3 sec
Qtr mile: 13.8 sec @ 104mph

Chrysler’s legendary 426 Hemi became a regular production option in 1966, and while show-offs could mate it with that year’s new Dodge Charger, drivers looking to fly under the radar would order it in a no-frills Plymouth Belvedere. Just imagine pulling up next to this in your Ferrari 275 GTB and watching it disappear into the distance while you wondered what the hell just happened.

Credit: Mecum

8. 1962 Ford Galaxie 406
Engine: 406 cu in (6.7-liter) V8
Power/torque: 405 hp/448 lb ft
Zero to 60mph: 6.5 sec
Qtr mile: 15.4 sec @ 93mph

Most of the early muscle cars were full-size cars, like this Galaxie 406. Spend $380 on the Thunderbird 406 High Performance V8 package and you got heavy-duty suspension, a bigger radiator and 15-inch wheels instead of 14s.

Go for the top dog Tri-Power triple-carb version of the big-block V8 and your 406 came with a crazy 11.4:1 compression ratio and 405 hp, all wrapped up in a sleepy-looking cruiser of a car you’d guess had half the horses.

Credit: Mecum

9. 1962 Dodge Dart 413
Engine: 413 cu in (6.8-liter) V8
Power/torque: 410 hp/460 lb ft
Zero to 60mph: 5.8 sec
Qtr mile: 14.4 sec @ 101mph

Surely one of the ugliest cars ever made, the 1962 Dart’s saving grace was its optional 413 cubic-inch Max Wedge V8. Thanks to high compression aluminum pistons and a cross-ram intake manifold, the hottest 413 made 410 hp, meaning most other cars would only ever see it from the back. Which is probably no bad thing.

Credit: Mecum

10. 1963 Plymouth Savoy 426
Engine: 426 cu in (7.0-liter) V8
Power/torque: 415 hp/470 lb ft
Zero to 60mph: 6.5 sec
Qtr mile: 13.7 sec @ 107mph

Featuring a stretched version of the aforementioned 413 V8, and much less gruesome styling than the Dodge Dart it was fitted to, the Plymouth Belvedere 426 was the precursor to the infamous 426 Hemi that would make its first appearance the following year.

With 415 hp on hand, and the ability to go sub-14 in the quarter mile, a basic Savoy like this was just about the fastest thing on the road in 1963. But who could possibly have guessed from looking at it?