In 1970, the muscle-car craze was at its peak, with a surge in horsepower and displacement. However, high insurance costs and legislative actions began to catch up with these powerful machines. The Chevelle SS, introduced in 1965, had gained significant popularity by the late 1960s and remained one of the most sought-after muscle cars in 1970. Chevrolet, responding to an internal GM edict, lifted restrictions on engine displacements larger than 400 cubic inches. This led to the introduction of the mighty 454 cubic inch V8 engine as an option for the 1970 Chevelle SS, making it a true freak of nature in the muscle car world.
The Birth of a Legend
Since its inception, the Chevelle SS had captured the hearts of muscle car enthusiasts. However, due to the engine displacement restrictions, the Chevelle SS models from 1965 to 1969 were limited to the 396 cubic inch big-block V8. Chevrolet found a way around this limitation through the Central Office Production Order (COPO) program, which allowed special orders for big-block 427 cubic inch V8 engines. This program was mainly utilized by racers and performance dealers such as Yenko. While the COPO program produced some legendary 427-powered Chevrolet muscle cars, their total production remained low.
The Arrival of the 454 Cubic Inch V8
General Motors decided to lift the displacement restrictions for the 1970 model year, and Chevrolet took full advantage of this opportunity. As a result, the 454 cubic inch V8 engine became available as an option for the 1970 Chevelle SS. The 454 V8 belonged to the Chevrolet Mark 4 big-block engine family. It was an all-new engine, with the legendary 427 big-block V8 being the largest Chevy V8 displacement in 1969. The increased stroke of the 427 engine led to a displacement of 454 cubic inches in the 1970 Chevelle SS, providing more power and torque to satisfy muscle car enthusiasts.
The SS Options
Chevrolet offered two separate SS options for the 1970 Chevelle. The Z25 SS 396 option included two versions of the Mark 4 396 cubic inch V8 engine: the L34 with 350 horsepower and the L78 with 375 horsepower. However, there was a secret concerning the 396 engines for 1970. They no longer displaced 396 cubic inches but rather 402 cubic inches due to a slight overbore. Chevrolet decided to name the 402 cubic inch engine the SS 454 or Z15. Mid-year, Chevrolet introduced two powerhouse 454 V8 engines for the 1970 Chevelle SS: the LS5 and LS6.
LS5 vs. LS6
The LS5 454 engine was rated at 360 horsepower in the 1970 Chevelle SS, but it produced390 horsepower in the 1970 Corvette. In reality, the LS5 engine in the 1970 Chevelle SS was identical to the LS5 engine in the 1970 Corvette. Initially, the 1970 Corvette was supposed to have the LS7 454 engine, rated at 465 horsepower, as its top engine option. However, Chevy canceled the LS7 and stuck with the LS5 for the Corvette. On the other hand, the LS6 engine, with its impressive 11.25:1 compression ratio, was factory-rated by Chevy at 450 horsepower and a remarkable 500 pound-feet of torque.
The LS6 engine featured various high-performance components, including solid valve lifters, a forged steel crank, TRW forged aluminum pistons, forged connecting rods, an aluminum intake manifold, and an 800 CFM Holley four-barrel carburetor. The power from the LS6 engine was transferred to the wheels through two available transmissions: the Muncie M22 Rock Crusher four-speed manual and the three-speed Turbo Hydra-Matic 400 automatic. Buyers could also choose from several performance rear axle options, with the most performance-oriented being the Positraction 4.10 rear axle.
Unleashing the Power
The 1970 Chevelle SS LS6 was a force to be reckoned with on the drag strip. In magazine tests of the time, the LS6 consistently achieved quarter-mile times in the 13-second range, which was incredibly impressive considering the LS6 Chevelle SS weighed around 4,000 pounds with the driver and fuel. Car Craft magazine recorded the fastest LS6 quarter-mile time in their November 1969 issue, with a bone-stock 1970 Chevelle SS LS6 completing the quarter-mile in 13.12 seconds at 107.01 miles per hour.
Power on the Road
The performance of the 1970 Chevelle SS LS6 was not limited to straight-line acceleration. With its heavy-duty F41 suspension, which included heavy-duty components, 14×7-inch wheels, and F70 tires, the LS6 handled turns with ease. Despite being a limited production car, with only 4,475 units sold out of a total of 62,372 1970 Chevelle SS models produced, the LS6 was highly regarded for its impressive performance on both the drag strip and the streets.
Style and Options
The 1970 Chevelle SS LS6 not only packed a punch under the hood but also turned heads with its stylish design. It featured a new front and rear end design, giving it a muscular appearance that matched its performance capabilities. The dual chrome-tip exhausts added to its aggressive stance. Buyers had the option to choose between the two-door coupe and convertible body styles. A notable addition for 1970 was the optional cowl induction hood (ZL2), which featured a solenoid-operated flap that provided cool air to the carburetor through the air cleaner assembly.
The Price of Power
In 1970, muscle cars were no longer stripped-down, bare-bones vehicles. The Chevelle SS LS6, with its array of available options, was no exception. Starting at around $4,500, the LS6 454 was an expensive purchase for the average buyer, considering the average family income at the time was around $10,000. However, for those who could afford it, the LS6 was worth every penny, offering unparalleled power and performance.
Conclusion
The 1970 Chevrolet Chevelle SS LS6 454 stands as a true freak of nature in the muscle car world. With its massive 454 cubic inch V8 engine, it unleashed power that left a lasting impression on automotive enthusiasts. Its incredible acceleration on the drag strip andits impressive handling capabilities made it a force to be reckoned with. The stylish design and available options added to its appeal. While the LS6 454 was a limited production car, it left a lasting legacy as one of the most iconic muscle cars of its time. Despite the decline of high-performance engines in the following years, the LS6 454 remains a symbol of power and performance in the golden era of muscle cars.
FAQs (Frequently Asked Questions)
1. How many units of the 1970 Chevelle SS LS6 454 were sold? Out of a total of 62,372 1970 Chevelle SS models produced, 4,475 units were equipped with the LS6 454 engine.
2. What is the difference between the LS5 and LS6 engines? The LS5 engine was rated at 360 horsepower, while the LS6 engine boasted an impressive 450 horsepower and 500 pound-feet of torque.
3. What transmissions were available for the 1970 Chevelle SS LS6? Buyers could choose between the Muncie M22 Rock Crusher four-speed manual transmission or the three-speed Turbo Hydra-Matic 400 automatic transmission.
4. Did the 1970 Chevelle SS LS6 handle well? Yes, the LS6 model featured heavy-duty suspension components, 14×7-inch wheels, and F70 tires, providing excellent handling capabilities.
5. How much did the 1970 Chevelle SS LS6 cost? The LS6 454 started at around $4,500, making it quite expensive for the average buyer in 1970.
