1970 Chevrolet Corvette C3

The late 1960s saw unprecedented escalations of horsepower and performance, peaking in 1970 with displacement sizes reaching 455 cubic-inches. The L78 engine in the 1965 Corvette displaced 396 cubic-inches and delivered 425 horsepower. By 1969, Chevrolet had produced its 250,000 Corvette, and the Tri-Power L71 had grown to 427 cubic-inches and 435 horsepower. A year later, the 427 was bored out to create the 454 cubic-inch LS5, greatly increasing low-end torque and improving acceleration from low operating speeds. Equipped with a hydraulic camshaft and a Rochester four-barrel carburetor, the engine delivered 390 horsepower and 500 lb-ft of torque.

The virtually unbridled grains of the 1960s had raised safety concerns, coupled with the forthcoming emission regulations, the advent of lead-free gasoline, ballooning insurance rates, and the oil embargo of 1973 brought this period to a close. During 1970, Congress passed the Clean Air Bill in the National Environmental Policy Act due to oil embargos and increasing government regulations about the fuel. This established regulations specifying fuel economy and emissions standards. By doing so, the big block faced extinction due to standards it could never meet. Toxic emissions were to be cut by 90 percent for all engines in less than six years.

The 1970 Corvette was delayed four months by a factory strike, and the motoring press' response to the new Stingray had prompted John DeLorean to resolve quality control issues. The new inspection regime succeeded in their task, but slowed production even more. Teams were mandated to correct any fault and every car was subjected to a pressure water bath to expose any leaks. The cars were driven over a cobbled road and then placed on a vibration table to reveal any creaks or other noises caused by flexing.

Along with quality, the 1970 Corvette interiors became more luxurious, easier access to storage, and redesigned seats that added headroom. Leather seats, woodgrain trim, and deep pile carpeting became available for the first time. The 327 cubic-inch small-block had been replaced in 1969 with the L46 350 CID version equipped with a Rochester four-barrel carburetor on a cast iron intake manifold, a hydraulic cam, and 11:1 compression to achieve 350 horsepower. For 1970, this engine was joined on the options list with the LT1. The ZR1 and ZR2 package was offered to satisfy the buyers who wanted a vehicle they could race. These vehicles were stripped of radios, power steering, power windows, and air conditioning. There was no hole for the antenna. The ZR2 used the LS6 454 cubic-inch engine, of which only 12 were purchased. The ZR1, based on the LT1, was offered from 1970 through 1972 with 53 total examples built. 25 examples were sold in 1970, eight in 1971, and 20 in 1972. Along with the LT1 engine, it came with the M22 transmission, J56 heavy-duty brake package with dual-pin front calipers, a special aluminum radiator with expansion tank, steel fan shroud, transistorized ignition, and a heavy-duty suspension package consisting of seven leaf rear springs, upgraded shock absorbers, 5/8-inch front sway bar, and heavy-duty rear spindle struts. The solid-lifter, small-block LT1 engine had 11:1 compression, a '178' high-performance camshaft and a 780 CFM Holley four-barrel carburetor mounted to a special aluminum intake. With 370 horsepower it was less-powerful than the L88 but offered plenty of excitement and performance on the racetrack. The cost of adding the ZR1 to the Corvette in 1970 was $968.95.

1,287 examples of the 1970 Corvette were equipped with the LT1 small-block V-8, which was available only with either the M21 close-ratio or M22 close-ratio heavy-duty 4-speed manual transmissions.

The 1970 Chevy Corvette had a base price of $5,190 for the Sport Coupe body style and $4,850 for the convertible. 10,668 buyers selected the coupe while 6,648 chose the convertible. The base engine was the 350 CID four-barrel V8 that had 300 horsepower and 380 lb-ft of torque. The LT1 and the L46 both shared the 350 cubic-inch displacement size as the base ZQ3, while the LS5 and LS7 displaced 454 cubic-inches. The L46 had 11.0:1 compression, four-barrel carburetor, hydraulic valve lifters, five main bearings, and 350 horsepower and 380 lb-feet of torque. The LS5 had a high-performance camshaft, Rochester 750CFM Qudra-Jet four-barrel carburetor, five main bearings, a 10.25:1 compression, 390 horsepower, and 500 lb-ft of torque. Only a single Corvette was built with the proposed LS7 engine with a high-performance camshaft and Holley 800CFM four-barrel carburetor. It delivered 465 horsepower at 5,200 rpm and nearly 500 ft-lbs of torque. Paul Van Valkenburgh, editor of Sports Car Graphic drove it 2,500 miles from a press conference at Riverside, California, to Detroit. It was capable of completing the quarter-mile in 13.8 seconds at 108 mph. Some early 1970 sales literature displayed the LS7 option, however, General Motor's policies against ultra-high-performance cars at the time meant that only one example was ever built.

The standard transmission in the 1970 Corvette was the Turbo Hydra-Matic transmission with floor-mounted gear shift controls. The close-ratio four-speed manual was a no-cost option, and over 70-percent of buyers selected this gearbox. The RPO M22 Heavy-Duty close-ratio four-speed manual was a $95 option. The N37 tilt-telescopic steering wheel was another fairly popular option, at $84.30, with 33.5 percent of buyers having it installed in their Corvette. 68.8 percent of buyers selected power steering and nearly 40-percent of all 1970 Corvettes were equipped with air conditioning.