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Hey! See that car directly above? The one doing a wheelie? That’s…

The Chevrolet Chevelle SS

In 1964 GM introduced another A-Body intermediate, the Chevrolet Chevelle. With a 115 inch wheelbase it was similar in size and complexity to the classic 55-57 Chevrolet Bel Air, but in a boxy ’60s style as opposed to the curves and fins of its ’50s forbearer. Chevelle was the US auto industry’s only all-new car for the ’64 model year.

First Generation 1964-1967

Unlike the strictly muscle car competition that arrived in the mid-’60s, the Chevelle was offered in a two-door coupe, a four-door sedan, convertible and station wagon models. The El Camino “utility coupe” with a pickup-like bed on a car chassis also fit into the Chevelle line, but with its own nameplate. The two-door models were dubbed “Sport coupes”, the four-doors “Sport sedans”. We will concentrate on the Super Sport (SS) models that were Chevrolet’s entry into the muscle car fray, but with occasional forays into lesser models.

The Malibu was the top-of-the-line Chevelle, so in ’64 the SS package had Malibu SS badging on the rear quarter panel. The SS package for the upscale Malibu also sported special exterior brightwork with SS emblems and the 14 inch full wheel covers from the Impala SS. The 283 cu. in V-8 produced 220 HP, coupled to a 3-speed manual, an optional aluminum 4-speed Muncie manual or a 2-speed Powerglide automatic. The Muncie 4-speed option also came with a floor-mounted console. Vinyl bucket seats and a 4-gauge instrument panel with an optional tachometer completed the SS package. In mid-1964 the Chevelle could be ordered with a 327 cu. in. V-8 producing either 250 or 300 HP.

1965 saw the 327 as a standard production option on the Chevelle. Mid-year a big-block 396 cu. in V-8 became available with the SS package, the SS 396. The L-37 396 had a forged crankshaft, 4-bolt main bearing caps, an aluminum intake with a Holley carb and a hydraulic camshaft. All of that was needed to contain the 375 HP that the L-37 put out.

In ’66 the Malibu SS badging disappeared except in Canada, and the SS 396 became a model in its own right. It used the same Malibu 2-door coupe and convertible bodies with reinforced frames and a revised front suspension: higher-rate springs, recalibrated shocks, and thicker front stabilizer bar, but with different exterior trim. They also had simulated hood scoops, red-stripe tires, and bright trim moldings. Three different 396 engines were available, the standard with 325 HP, and two optional with 360 and 375 HP. Early sales documents did not list the 375 HP option, however, but the later addendum made dealers aware. Transmission options were the same as on the ’65.

The Chevelle got a facelift in ’66 also, with a new grill and bumper design, along with a more raked roof line with a “flying buttress” rear (tunneled into the “C” pillar) on the hardtop, chrome accents, and curved side windows that gave it a look that many still flock towards. This reflected the “Coke-bottle” shape that was all the rage for American automakers in the mid-’60s. The ’66 SS 396 was also the first year that two simulated scoops were installed on the hood. These twin scoops would go on to become a signature SS feature for the following years.

When the 1967 model-year Chevelle was released it featured a new front-end design with the fenders having a protruding edge, and a grille that jutted forward with them. The tail lights also wrapped around the rear corners of the car, and were squarer as opposed to the long rectangular shape of the previous year.

Engine options changed for the SS 396 in ’67. The 375 HP L78 engine was dropped as a factory option, the only two engine choices were the base 325 HP version or the L34 that now delivered 350 HP instead of the 360 HP of the ’66. Some say it was a marketing decision to please the corporate people at GM and that there was no actual reduction in horsepower. That being said, it has been reported that approximately 612 cars did receive the L78 engine as a dealer-installed option. Transmission options changed as well, in addition to the base 3-speed manual, the four speed was once again available in a wide-ratio Muncie M20, the close-ratio M21, or the beefier-built M22 Rock Crusher. This was the first year that a three-speed automatic transmission was available in the SS 396 Chevelle. RPO M40 got you the 3-speed Turbo 400 automatic transmission, but the Powerglide was still the standard automatic transmission in all Chevelles.

It’s interesting to note the engine options available for non-SS 396 Chevelles as well. In ’67 there was a plethora of choices; the previous year’s standard 194 cu. in. six cylinder had been dropped from the lineup, making the 140 horsepower 230 cu. in. six cylinder the Chevelle’s base engine. However, there was a new choice for those wanting the six cylinder engine, as buyers could now get the 250 cu. in. version with 155 horsepower. While the four-barrel equipped 283 cu. in. V-8 engine was also dropped, a 283 engine was still available, but only with the Rochester two barrel carburetor.

With 195 horsepower, the 283 was handily choked in the power department, but a 327 V-8 engine with 275 horsepower was also offered.

Second Generation 1968-1972

In 1968 the Chevelle got a radical restyling, along with other GM A-Body intermediates. Gone was the boxy style of previous years, replaced with an all-new distinctly sculpted body with tapered front fenders and a rounded belt line. The wheelbase was reduced from 115 inches to 112. Hardtop coupes featured a semi-fastback, flowing roofline, and a long hood and short rear deck with a high rear-quarter “kick-up”, mimicking the Camaro introduced the year before.  Side marker lights became mandatory in 1968 also. Top-trim models (including the SS 396 and new luxury Concours) featured GM’s new Hide-A-Way wiper system. Lesser Chevelles would get that change later.

The SS 396 package gave three engine options instead of two as in the previous year.  The base 396ci engine again delivered 325 horsepower, and the optional L34 delivered 350 horsepower. Both featured Rochester Quadrajet carburetors, a 10.25:1 compression ratio, and two-bolt-mains. The 375 horsepower L78 396ci engine was once again the big-dog option, and brought with it 11.0:1 compression ratio, mechanical lifters, and a Holley four-barrel carburetor with an aluminum intake. While all 396ci engines had the option of receiving chrome valve covers, only the 350 and 375 horsepower versions carried an open-element air filter.

V-8 options changed for the non-SS 396 Chevelles as well. The standard V8 was now the new 200 horsepower Turbo-Fire 307. This new V8 was developed so that Chevrolet could comply with increasing federal emissions regulations and a consumer demand for better fuel economy. The 307 has a 3.875-inch bore (same as the 283) and 3.250-inch stroke (same as the 327). The cylinder heads used the small 1.940/1.500-inch valves, and had a smaller quench area than other small block cylinder heads. The 307ci engine was only available with a two-barrel Rochester carburetor.  Three 327 cu. in engines were now offered, a 250 horsepower Turbo-Fire 327, the 275 horsepower Turbo-Fire 327, and the 325 horsepower Turbo-Fire 327.

I owned a Malibu model ’68 Chevelle painted Cordovan Maroon Metallic for a few years in the early ’80s. It was unfortunately not an SS 396, but it did have the 325 HP 327 which put out the same power as the base 396, albeit with less torque than the big-block. It also unfortunately had the 2-speed Powerglide transmission, which was the only automatic available with the small-block V-8. This was not the ideal transmission for getting the 327’s 325 HP to the rear wheels, but I dealt with it. It was a blast to drive, even with manual steering (ugh) and was the highest horsepower engine I have ever owned. It had factory air conditioning, a must in Georgia where I bought it in the summertime. When I dropped my right foot it scooted right down the road at one hell of a clip, A/C or no.

A few front and rear end changes were all the differences in 1969 from the ’68 body style, including a single chrome bar connecting the quad headlights with a revised front grill, now cast in ABS plastic, and a slotted bumper that held the parking lights. Taillight lenses were larger and more vertical, flowing into the quarter panels. The side markers were smaller this year.

The SS 396 retained its 325, 350 or 375 HP form. A more powerful option this year was an L72 427 cu. in. engine putting out 425 HP. An estimated 323 Chevelles were so equipped, 99 of which were sold by the Yenko Chevrolet dealership in Canonsburg, PA. Don Yenko’s Chevrolet dealership sold 427-equipped Chevelles and Camaros in 1969 that bore special graphics in addition to the big-block 427. These Yenkos are some of the most desirable and valuable Chevrolets ever produced.

1970 saw more changes to the sheetmetal as the bodies were more “squared up” instead of Coke-bottle like. The ’70 Chevelle also shared many body parts with the Buick Skylark GSX, the only two muscle cars to share the same roofline. The base SS 396 offered a 350 HP 396 engine, a “power dome” hood, black accented grill and wide oval tires on sport wheels. The other engine offered in the SS 396 package was a 330 HP V-8 that was actually 402 cu. in. but still marked as “SS 396”. The 427 engine of 1969 was not offered, replaced by a 360 HP LS5 454 and packaged as the SS 454. Both the SS 396 and SS 454 could be had with cowl induction, which opened a scoop on the rear of the hood cowl to allow cool air into the intake.

Front and rear end changes came again for the 1971 model including a switch to single headlights and integrated parking/side marker lights on the corners. The grill was widened and a bright horizontal bar now ran through the middle with an SS emblem in the middle for the SS package and a Chevrolet bowtie for lesser Chevelles.

Mid-year Chevrolet introduced the “Heavy Chevy” option for the standard Chevelle in which buyers could order any V-8 offered except the 454, that engine being available only on the SS option, but interiors were limited to base Chevelle options. Engine options in ’71 were detuned to be able to run on the new unleaded gasoline, compression now being lowered to 9:1 or below from the 10.25:1 or 11.25:1 the year before. Horsepower was now being rated as both gross and net, net taking into account standard intakes and the exhaust system. The SS option could be ordered with any V-8 except the base 307 and became more of a dress-up option than a performance option: the 402 was down to 300 gross (260 net) HP and even the 454 only produced 365 gross (285 net) HP. It only achieved that number thanks to the cowl induction feature not available on other SS engines.

The 1972 front grille now sported twin-bar grilles, and all Malibus had hidden wipers. The SS option could be ordered with any V-8 except the 307 as in ’71. Engines were now rated only in net HP, and HP was down even from the net ratings of 1971. The 402 (still marketed as a 396) was down to 240 net HP and the 454 down to 270. The 307 and 350 cu. in engines were down on HP as well. 1972 was the last year for the cowl induction on the 454 SS package and not even included in the Chevelle brochure.

Third Generation 1973-1977

In 1973 Chevelle saw the most extensive redesign in its history, following the other A-Body GM intermediates. New Federal rollover standards meant that the convertible and 4-door hardtop models were dropped, leaving a 2-door “pillared coupe” with a semi-fastback design, fixed rear windows and a styled B-pillar and station wagon as the only options. Federally mandated 5 MPH crash safety regulations resulted in large chrome bumpers and side-impact beams in the doors as on other ’73 cars. Front disc brakes were now standard. Any Chevelle could now be had with any engine, gone were the days of SS only big-blocks. The SS option was now merely a trim package, even available on the station wagon.

Horsepower was down even more for ’73: the 454 down to 245, the 402 cu. in. “396” was gone, and the two 350 options were disappointments: 145 HP for the 2-barrel model and 175 for the 4-barrel. We won’t even mention the 307.

1974 and 1975 were more of the same, grills and taillights being the only changes, although Federal safety standards dictated larger rear bumpers as well from 1974 onward. The 454 dropped to 230 HP as other engine options had reduced HP also.

1976 saw the introduction of a new 140 HP 305 cu. in engine to replace the aging 307. The only other V-8 options were a 165 HP 350 and a 175 HP 400. The gas crisis and higher insurance rates had effectively killed the horsepower wars of the late ’60s and early ’70s.

1977 was the final A-Body to wear the Chevelle name, in 1978 it was dropped in favor of Malibu. New grills were again the only real external difference from previous years. Engine HP was up slightly to 145 for the 305 and 170 for the 350, well below even the modest 200 HP 1970 307-equipped Chevelles.

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Seeyas next time on FLAT OUT!

It’s Jeff Despicable Boofer


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