Why did the Pontiac Tempest Le Mans GTO become the pioneer of the muscle car era even though there were already big-block engines before 1963? (Yes, I am aware that the GTO did not have a big-block engine because it did not have a large V8 engine. Pontiac only had one eight-cylinder engine block, regardless of its size in passenger cars). There is no need to answer; there is nothing we can do about it, so let’s just forget about that detail.
Instead, let’s focus on the fact that the Impala made its debut at the same time as another significant milestone for General Motors’ bowtie division: the introduction of the 348 V8 engine. This nameplate made its debut on October 31, 1957. It had a rough start, with the world’s attention captivated by another historic event: the official start of the space race between the U.S.A. and the U.S.S.R.
Just four weeks before the launch of the high-end Chevy subseries, the Soviets successfully placed the first artificial satellite into orbit, marking a major advancement in the space age. With this in mind, the introduction of one more Chevrolet wouldn’t have made much of a difference. Or would it?
The Soviet space program, which was overly ambitious, eventually came to an end (just like the entire Union). However, the Impala remained on the market for a while. After its initial year, it became a standalone model in the 1958 lineup. Coinciding with the fresh Chevy name, the introduction of the equally impressive big-block engine (the first for a Chevrolet passenger car) could have significantly influenced buyers’ perception of the car.
The 348 engine was first introduced in October 1957, initially intended for use in trucks only. However, the horsepower competition was still ongoing, and Chevrolet decided to up the ante by increasing the engine’s cubic inches.
By 1960, the legendary engine (with a displacement of 5.6 liters) was ready to deliver impressive power, thanks to various upgrades such as dual four-barrel carburetors, revised cylinder heads, and a high-performance exhaust system. The best factory option was a three-barrel 348 engine paired with a four-speed manual transmission. Just like the example showcased in the recent video, this car boasts exceptional performance under its large hood.
This particular car is owned by a former car enthusiast with a penchant for speed and a proven track record in drag racing. The bubble top Impala is in its best possible condition, having undergone a meticulous restoration process. The original panels were carefully removed and painted individually. The engine has also been enhanced with ported and polished cylinder heads, a roller camshaft, and Rocket roller rocker arms. Experience the exhilarating sound of this car in the video below as its owner expertly revs the engine.
The V8 vehicle, painted in white and red, housed the 348 engine with triple fuel injection and a compression ratio of 11:1. This results in an output of 340 horsepower and undisclosed torque figures (the specific numbers are not mentioned by the owner). Historically, the most powerful version of the 348-cubic inch engine that could be obtained from the factory had a power output of 335 horsepower (349 PS) and a torque of 356 lb-ft (483 Nm). It featured Tri-Power three-two barrel carburetors and a compression ratio of 11.25:1.
The current owner has possessed the car since 2017, acquiring it after an extensive search and subsequently restoring it to some extent. The odometer indicates a mileage of 62,184 miles (equivalent to just over 100,000 metric kilometers). The Impala appears dazzling, radiant, adorned with chrome, and possesses an awe-inspiring level of performance. The rear differential is equipped with a 3.55 gearing and the Positive Traction anti-slippage mechanism.
Although Chevrolet manufactured over half a million vehicles in 1960, the production records do not provide a breakdown of the different body styles. Hence, determining the exact number of bubbletop models requires some investigative work. According to the owner of this remarkable specimen, who was filmed by Lou Costabile last autumn, he has only encountered another one in the Chicago area.
According to the Source autoevolution.com