Chevrolet Chevelle Generation 2 SS396 402/350 L34 Coupe 1970
Car producer :  |
Chevrolet |
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Model: |
Chevelle Generation 2 SS396 402/350 L34 Coupe 1970 |
Year: |
1968-1972 |
Type: |
Coupe |
In 1970, sheet metal revisions gave the bodies a more squared-up stance and interiors were redesigned, too. 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 3 of these (Malibu sport coupe, Malibu convertible and El Camino pickup) were available with a choice of one of 2 SS options; RPO Z25 with the SS 396 (402cid) engine and RPO Z15 with the new 454cid engine. The SS options were limited to the Malibu two-door sport coupe, Malibu convertible and El Camino pickup. The base model Chevelle was now named Chevelle (which causes confusion) in lieu of the former base 300 Deluxe and was only as a sport coupe or four-door sedan.
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. 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 402cid engines but was still marketed as a 396. The second 402cid engine was available under RPO, rated at 330hp 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 454cid engine and was only available with the RPO Z15 SS Equipment option. The base 454cid engine was rated at 360hp (which was also available with cowl induction) and the optional LS6 version at 450 hp. There were 4,475 LS6 Chevelle's produced, of which 137 are currently registered on the National Chevelle LS6 Registry.
The newly redesigned 1970 Chevelle SS, with its robust body-on-frame construction and 112-inch wheelbase, was the perfect platform for the incredible LS6 engine, which was underrated by Chevrolet at 450 horsepower and 500 pounds-feet of torque. With its 11:25:1 compression ratio, big-valve cylinder heads, 780 cfm Holley carburetor, and radical solid-lifter camshaft, the new 454 was supported by a stout four-bolt main block and a forged reciprocating assembly, and backed by either an M-22 “Rock Crusher” four-speed manual transmission or a hard-shifting M40 Turbo Hydra-Matic 400 automatic. Depending on rear-end gearing, which ranged from 3.31:1 to 4.10:1 at the factory, LS6 Chevelles were capable of easy 13-second quarter-mile times, with traction severely limited by the bias-ply tires of the day. Fuel economy was 10 miles per gallon at best, and annual insurance premiums approached one-third of the purchase price of the car. Clearly, economy and cost-effectiveness were not its objectives. In fact, Hot Rod Magazine summed up the car best in a 1970 road test, entitled “Earth Mover”.
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 in the October/November 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. It has been suggested that the LS6 was substantially "under-rated" and actually produced something on the order of 500 horsepower (370 kW) as delivered from the factory. Recent engine dyno tests have proven that the 1970 LS-6 engine makes over 450hp and 500 lb/ft torque in stock configuration (stock compression ratio, stock camshaft, and stock intake and exhaust manifolds).
"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 360hp (270 kW).