1970 Oldsmobile 442 W-30 Convertible
Unlike most engines of the postwar period, the Oldsmobile 455 is undersquare, i.e., the stroke is longer than the bore. Having a long stroke engine tends to make the torque curve peak early in the rpm range; conversely, a short stroke engine will be inclined to rev higher and have higher torque peak. The advantage of an engine that has loads of torque at low rpms is that the surge of power is immediate from the moment that you step on the accelerator. While there are many cars from then to now that handily outperform the W-30 on paper, the number of cars that have that same sense of immediate power are far fewer. It's an intangible that makes the W-30 an enormously fun car to drive on the street.
The only other muscle car of that era to equal the maximum torque numbers is the 1970 Buick GS. Even today, very few naturally aspirated cars match or exceed the 500 lb-ft of the 1970 W-30.
The W-30 was an option package on top of the 1970 Oldsmobile 442 model. Features over the regular model included an engine with 5 more horsepower and an aluminum intake manifold, red fiberglass inner fenderwells, and fiberglass OAI hood.