During the 1960s and early 1970s, American manufacturers engaged in a high-performance war that gave birth to some of the most iconic production cars of all time.
Muscle cars, equipped with potent V8s, made outrageous output figures, at least by 1960s and 1970s standards.
Peak horsepower is the unit that everyone remembers, but torque is also important. Let’s remember the five most torquiest production V8s of the muscle car era.
Chrysler 426 HEMI V8 – 490 lb-ft (664 Nm)
Chrisler’s second-generation V8 with hemispherical combustion chambers, the 426 HEMI, started life as a race engine that helped Plymouth dominate the 1964 NASCAR season.
Since it wasn’t used in a production car, the legendary engine was banned from the competition for the 1965 season. Chrysler had to develop a street version and make it available to the car-buying public.
Thus, for the 1966 model year, the so-called street HEMI was unleashed. Equipped with dual inline four-barrel Carter AFB carburetors, the 426-ci (7.0-liter) big-block V8 was rated at 425 hp and 490 lb-ft (664 Nm) of torque.
Produced until 1971, it was available in Plymouth and Dodge’s meanest intermediates as well as the most potent versions of their E-body pony cars.
Chevrolet 454 LS5 and LS6 V8 – 500 lb-ft (678 Nm)
For the 1970 model year, GM ended its self-imposed ban on V8s larger than 400 ci (6.4 liters) on intermediate models, allowing engineers to upgrade their muscle car big-block V8s.
At Chevrolet, the new range-topping V8 became the 454 (7.4 liters), which could be had in one of two configurations.
The first, available on the Chevelle SS, El Camino SS, Monte Carlo, or the full-size Caprice and Corvette sports car was the LS5, rated at 360 hp (390 in the Corvette) and 500 lb-ft (678 Nm) of torque.
If those figures weren’t enough, Chevelle and El Camino SS customers could get the LS6 454. Upgraded with a hefty list of high-performance hardware, this 454 was capable of producing 450 hp and the same 500 lb-ft (678 Nm) of torque.
Pontiac 455 HO V8 (D-port) – 500 lb-ft (678 Nm)
GM’s decision to lift the 400-ci (6.5 liters) ban in 1970 also made Pontiac engineers busy.
In an exciting twist for the model year, the iconic GTO introduced the powerful D-port 455-ci (7.5 liters) HO (High Output) V8 engine, boasting an impressive 360 hp and 500 lb-ft (678 Nm) of torque.
The Pontiac 455 continued to thrive throughout the 1970s, making appearances in the high-performance Trans Am. However, its power and torque ratings were slightly lower than before.
As the years went on, strict emission regulations took a toll on the 455’s performance, further reducing its power and torque capabilities.
Sadly, the large-displacement V8 met its demise at the end of the 1975 model year due to increasing emission regulations and the need for improved fuel efficiency.
Oldsmobile, on the other hand, took a unique approach by bypassing the ban on the 400-ci (6.5 liters) engine. Instead, they installed a 455 originally intended for their full-size models into a high-performance intermediate vehicle.
The 1968-1969 4-4-2-based Hurst/Olds was the lucky recipient of the 455-ci (7.5 liters) Rocket V8, a result of Hurst Performance’s involvement. This potent engine delivered 390 hp and 500 lb-ft (678 Nm) of torque.
In 1970, Oldsmobile finally had the opportunity to incorporate the 455 into the 4-4-2, resulting in a standard output of 365 hp and 370 hp with the W-30 option. The torque rating remained unchanged.
Buick also made its mark in the muscle car era with the introduction of the Gran Sport and GSX models. Their specially developed 455 engine packed a punch with a base rating of 350 hp and 360 hp with the Stage 1 option.
Unlike its counterparts from Pontiac and Oldsmobile, the Buick 455 V8 was able to generate an impressive 510 lb-ft (691 Nm) of torque, making it the most torque-heavy production V8 of its time and holding that title for the next two decades.
However, the Buick’s reign as the torque king came to an end in the early 1990s when the Dodge Viper’s engine, equipped with two extra cylinders, surpassed its torque output.
