The golden muscle car era spawned a long list of powerful machines, some with more than 400 horsepower on tap. Chrysler had several 400+ horsepower nameplates in showrooms thanks to the 426-cubic-inch (7.0-liter) HEMI V8, rated at 425 horsepower. The L72 in the Chevy Camaro also delivered 425 horses, while the all-aluminum ZL-1 provided 430 horses. But none of these mills were as potent as the 454-cubic-inch (7.4-liter) LS6.

Introduced in 1970, it found its way into the Chevrolet Chevelle SS in two flavors. The LS5 delivered 360 horsepower, a rating that placed it below the 375-horsepower 402-cubic-inch (6.6-liter) V8 in the SS 396. But the higher-compression LS6, topped by a four-barrel 800 CFM Holley carburetor, delivered a whopping 450 horses. Torque was just as impressive at 500 pound-feet (678 Nm).

These figures turned the Chevelle SS 454 LS6 into the most powerful factory car of the era, a benchmark that would stand for decades due to the Malaise Era that followed. The LS6 was also a one-year gem, as Chevy discontinued the mill for the 1971 model year. And because it was quite expensive, it was ordered in small numbers, making it a rare powerplant nowadays.

Chevrolet sold 4,475 LS6-equipped cars in 1970, which is only 1% of the total production that year. This figure also includes El Camino pickups. Chevrolet didn’t keep detailed records, but Chevelle experts agree that fewer than 4,000 hardtops and convertibles left the assembly line with this engine. The drop-top is by far the rarest.

Again, there’s no official production number to discuss, but most authorities place the figure at around 20 to 25 examples, with fewer than that known to still exist. Not surprisingly, the SS 454 LS6 Convertible is a highly expensive classic nowadays.

Restored and highly original examples have been changing hands for more than $400,000 in recent years, and three units even broke the half-million dollar mark. The most expensive unit crossed the auction block for $572,000 in January 2022. Exactly a year later, another drop-top sold for $550,000. The Misty Turquoise drop-top you see here sure looks like one of those half-million-dollar Chevelles, but there’s a catch.

A fabulous restoration with only 170 miles (274 km) on the odo since it came off the rotisserie, this two-door hides a fully-fledged 454-cubic-inch LS6 under the hood. It also rocks all the correct LS6 features, including the badges and the 6,500-rpm redline tach. But this Chevelle wasn’t born this way. But while the powertrain is period-correct, this Chevelle wasn’t born as a 454 LS6.

I’d say that’s a shame because whoever restored this rig did a tremendous job. And the color combo itself is quite rare. Misty Turquoise is a hue we rarely see on 1970 Chevelles, and I’m pretty sure an LS6 Convertible with this color combo (including the white interior) would have been a one-of-one gem.

But I’m not at all disappointed that this drop-top is only an LS6 impersonator. It’s a fine build and a very cool tribute to the muscle car era’s most potent factory car. And at $129,998, it’s significantly more affordable than a fully-fledged LS6 convertible