The Chevrolet Chevelle is a mid-sized automobile which was produced by Chevrolet in three generations for the 1964 through 1978 model years. Part of the General Motors (GM) A-body platform, the Chevelle was one of Chevrolet's most successful nameplates. Body styles include coupes, sedans, convertibles and station wagons. Super Sport versions were produced through the 1973 model year, and Lagunas from 1973 through 1976. After a four-year absence, the El Camino was reintroduced as part of the new Chevelle lineup in 1964. The G-body Monte Carlo, introduced in 1970, also used a platform that was based heavily on the Chevelle platform, although it was lengthened ahead of the firewall. The Malibu, the top of the line model through 1972, completely replaced the Chevelle nameplate for the redesigned, downsized 1978 model year.
In 1970, sheetmetal revisions gave the bodies a more coke bottle styling, and interiors were also redesigned. The 1970 Chevelle and the 1970 Buick Skylark share the same roofline. The 1970 Chevelle came in Sport Coupe, Sport Sedan, convertible, four-door sedan, a couple of wagons, and coupé utility (the El Camino) body styles. Only three of these (Malibu sport coupe, Malibu convertible and El Camino pickup) were available with a choice of one of two SS options; RPO Z25 with the SS 396 (402 cid) engine and RPO Z15 with the new 454 cid engine. The base model was now simply called Chevelle in lieu of the former base 300 Deluxe, and was only available as a Sport Coupe or four-door sedan. In Canada, the base series retained its 300 Deluxe name, with appropriate badging on each front fender just behind the front wheel well. The 300 Deluxe 2-door sedan was cancelled and replaced by the base Chevelle Sport Coupe, a 2 door pillarless hardtop. The hardtop, convertible, and sedan received the upgraded sheetmetal but the station wagons and El Camino retained the previous year sheetmetal panels (which went on for the next 2 model years). Station wagons were the entry level Nomad, the Chevelle level Greenbrier, the Malibu level Concours and an upscale Concours Estate. New options included power door locks and a stalk-mounted wiper control. Production was expanded to the GM Arlington Assembly plant in Arlington, Texas (where the Chevelle was assembled with its corporate siblings in this case the Oldsmobile Cutlass).
Engine choices ranged from the standard 155 horsepower (116 kW) six-cylinder and 200-horsepower 307-cubic-inch V8, to a pair of 350 V8s and a pair of 402 engines. RPO Z25 SS equipment option included one of these 402 cid engines but was still marketed as a 396. The second 402 cid engine was available under RPO, rated at 330 hp with single exhaust, and was available in any V8 series except an SS optioned Malibu or El Camino. 1970 also saw the introduction of the 454 cid engine and was only available with the RPO Z15 SS Equipment option. The base 454 cu in (7.4 L) engine was rated at 360 bhp (365 PS; 268 kW), which was also available with cowl induction; and the optional LS6 version equipped with a single 4-barrel 800 CFM Holley carburetor produced 450 bhp (456 PS; 336 kW) at 5600 rpm and 500 lb⋅ft (678 N⋅m) at 3600 rpm of torque.There were 4,475 LS6 Chevelles produced.
The SS 396 Chevelle included a 350 horsepower (260 kW) Turbo-Jet 396 V8, special suspension, "power dome" hood, black-accented grille, resilient rear-bumper insert, and wide-oval tires on sport wheels. Though a 375 horsepower (280 kW) cowl induction version was available, few were sold in favor of the newly introduced 454 engine during late-1969 timeframe. The LS5 454-cubic-inch V8 produced 360 horsepower (270 kW) in standard form and a cowl induction version was also available. The LS6 produced a claimed 450 gross HP in solid-lifter, high-compression guise.
"You can make our tough one even tougher," the brochure explained, by adding Cowl Induction to either the SS 396 or the SS 454. Step on the gas, and a scoop opened "to shoot an extra breath of cool air into the engine air intake....like second wind to a distance runner." Neither functional hood lock pins nor hood and deck stripes were standard with either SS option, but were part of the optional ZL2 cowl induction hood option. The 454 cu in (7.4 L) LS5 V8 was rated at 360 hp (270 kW).