Wednesday, October 3, 2012
The public introduction of the Chevrolet Impala took place in 1956 when the one-of-a-kind Impala show car debuted at the General Motors Motorama. The sporty four-passenger coupe had a strong Corvette flavor and was referred to as the “Corvette Impala” in some of the motoring press. The Impala was originally conceived as a Bel Air executive coupe. The year was 1958. At Chevrolet and throughout the auto industry, change was in the air. GM's legendary styling chief Harley Earl had left an indelible mark on Chevrolet.
In 1958, Chevrolet introduced its new full-size passenger cars, redesigned from the ground up with a new frame and sheet metal. A new uplevel, sporty trim package was created for Bel Air coupes and convertibles, along with a new name - Impala. The Impala began as the top option level on Chevrolet's Bel Air line. Chevrolet's 1958 lineup featured one-year-only styling that sported "curves where before there were lines." The Impala option added special trim, deluxe interiors, and resulted in the steepest price in the Chevrolet lineup. Performance was important from the beginning as the first Impala could be optioned with up to a 348 V8 putting out 315 bhp. The public's positive response lead to Chevrolet making the Impala a separate option for the next year. Chevrolet produced 125,480 Bel Air Impala coupes and 55,989 convertibles in model-year 1958. The Impala brand was born. To consumers, Impala offered an uplevel image that was still within an affordable price range. From the beginning, the Impala nameplate carried with it images of fun, youthfulness, spontaneity and pride.
The Impala became its own model in 1959 with both two and four-door versions. Chevy’s radically restyled 1959 passenger models were a big surprise, rendering the all-new 1958’s obsolete. The “stealthy” theme of the 1959 press kit only hinted at the wild changes in store. According to press materials of the day, mechanical advancements of improved brakes, new suspension and easier handling point to a luxury liner that is marked for top popularity. As with all 1959 Chevy's, the new Impalas were longer, lower, wider, and curvier. Chevy’s bold new face dropped the headlights seven inches from 1958 to the minimum height allowable. Interiors gained nearly five inches in width. They also had the wildest tailfins besides Cadillac. The rear end sported "bat wing" rear fenders, "cat's eye" taillamps, and a huge decklid. The drivetrain stayed the same, with some increases in horsepower and sales remained good. Of particular interest to enthusiasts were the availability of fuel injected 283 V8's, although these were rare. Impala became America's best seller just one year later.
The Impala was toned down for 1960 and lost some of their distinct styling. Chevrolet changed almost every body panel on its 1960 cars except the roof. GM designers later admitted that they knew they’d gone too far, hence the more conservative approach for 1960. The “cat’s eye” taillamps were replaced by three round cone shaped taillamps per side and the gullwing fins were toned down.
By 1961, tail fins were gone on Chevrolet models, chrome trim was subdued, and the outspoken designs of the '50s gave way to cleaner, crisper, faster-looking edges, and streamlined, rocket-like shapes. Bill Mitchell's styling vision was evident. The Impalas were finless for 1961 and the Impalas retained the three-lamp motif at the rear. 1961 would be the year that the first true muscle car was introduced, the Chevrolet Impala SS. A mid-year option on the 1961 Impala was the Super Sport which was available on all body styles. In subsequent years the SS is limited to only sport coupes and convertibles. The SS package in 1961 was truly a performance package. Nothing less than the high-performance 348 engines or the new 409 could be ordered. The 348 options were 305, 340 and 350 horsepower engines. It consisted of upgraded tires on station wagon wheels, springs, shocks and special sintered metallic brake linings. Power brakes and steering were also included. This would also be the year that Chevrolet introduced its 409 cubic inch V8, the engine that would launch the Big Three auto manufacturers into the horsepower race that would last well into the 1970s. The 409 was a bored and stroked version of the 348, rated at 360 hp on a single 4 barrel and was known as the Turbo-Fire 409. A true performance engine, the 409 came with an aluminum intake manifold, a Carter four-barrel carburetor, a solid lifter camshaft and an 11.25:1 compression ratio. A total of 142 cars got this engine in 1961. In the interior, the SS package consisted of a passenger’s-side grab bar with the Impala SS script, a 7000 rpm steering wheel mounted tachometer, a shifter plate for four-speed-manual equipped Impalas and a dash panel pad. The Impala SS could be identified by SS emblems on the rear fenders and trunk lid. Wheel covers were unique, featuring three-blade knock-off type spinners. The 409 was actually a response to Ford's new 390 cid engine, which was outperforming Chevy's on the dragstrip. Although it put out "only" 360 bhp compared to Ford's top 375 bhp, those extra 19 cid gave it respect on the street and immortalized in song ("She's really fine, my 409"). Chevrolet introduced the Super Sport (SS) option package, which was optional on the 348 and standard with the 409, which would define Chevrolet performance for many years to come. The Super Sport package, a bargain at just $53.80, consisted of special body and interior trim, power steering, power brakes with sintered metallic linings, full wheel covers with a three blade spinner, a passenger grab bar, a console for the floor shift, and a tachometer on the steering column. The 409 engine came only with the four-speed manual transmission and only one factory axle ratio. Lower axle ratios were available from the dealer and owners could see 1/4 mile times in the high 15s, which was pretty impressive in 1961.
In 1962 the option of the Super Sport was available on only the two-door coupe and convertible. However, the SS models in 1962 could have any engine from the standard 235 ci six to the 409 big block V-8. (Impala SS engine options included the 235ci 135hp I-6, 283ci 170hp V-8, 327ci 250 V-8, 327ci 300 V-8, 409ci 380hp V-8 and the 409ci 409hp V-8.) Horsepower ratings on the 409 ci V-8’s were upped to 380 on the single four barrel and 409 on the 2 x 4 barrel. The heavy duty mechanical items of the 1961 Super Sport option (HD springs, shocks, brake linings, etc.) were deleted in 1962, though they were available optionally. Chevrolet increased production of the 409 and made it available in all full size Chevy's - Biscaynes, Bel Airs, and Impalas. The Impala Sport Coupe came with a ribbed rear roof line and a smaller back window to mimic the look of a cloth convertible top. The Impala's were a bit less aerodynamic this year, which made some racers turn to the lighter and slicker Bel Air coupe. The biggest change from 1961 was that the front bucket seats with a short console between became a part of the SS package in 1962. On the exterior, the most noticeable difference between the Super Sport Impala and the regular Impala was the use of aluminum body molding inserts; plain Impalas came with painted inserts. The rear fender SS emblems were redesigned. For 1962 the SS letters with red inlay were positioned over the circular Impala emblem. An Impala SS emblem was located on the right rear part of the trunk. The 409 was improved by adding new cylinder heads and a revised camshaft. With the standard 4 bbl carb, the 409 produced 380 bhp. But the real news was the improved top of the line 409 which added a pair of Carter AFB four barrel carbs and a lightweight valve train, and produced an astonishing 409 bhp, or a magical 1 bhp per cid. The 409 legend grew.
1963 saw the Impala SS continue to increase in performance and popularity. With the elimination of the Bel Air coupe, buyers again switched back to Impala SS coupes and convertibles. (Impala SS engine options included the 230ci 140hp I-6, 283ci 195hp V-8, 327ci 250 V-8, 327ci 300 V-8, 409ci 4 bbl 340hp V-8, 409ci 4 bbl 400hp V-8, 409ci 2x4bbl 425hp V-8 and the 427ci 2x4bbl 430hp V-8.) The 409 was further improved for driveability and a detuned version with 340 bhp was made available with an optional Powerglide automatic transmission. For the serious enthusiasts, Chevrolet offered the 409 with solid lifters and a single four bbl carb good for 400 bhp and a solid lifter 409 with two four barrel carbs good for a whooping 425 bhp. As if that wasn't enough, Chevrolet introduced a new engine, the Z-11 in mid 1963. This was a 427 cid V8 loosely based on the existing 409 but featured a smaller bore and a longer stroke. It featured angled valves and was nicknamed the "porcupine head motor." Although it was officially rated at 430 bhp, it easily made close to 500 bhp and was an instant success at the drag strip. Unfortunately, it was only available to factory approved customers through Chevrolet's RPO (Regular Production Option). It was usually coupled with the optional factory fitted lightweight front end - aluminum panels and bumper. In addition, Chevrolet was preparing another 427 V8, the Daytona "Mystery Motor" to be used at the 1963 Daytona race. However, Chevrolet officially withdrew from racing competition, putting a stop to development of the "Mystery Motor" and after only 55 Z-11 Impalas were built. The 427 would not reappear for another three years, but it would be a direct descendent of the "Mystery Motor" that Chevrolet had killed in 1963.
The Impala SS became its own series (separate model rather than an option package) for 1964 and continue to feature unique exterior trim and a lavish interior. A slight redesign distinguished the 1964 Impala, giving the car a more boxy, formal look. The Impala SS received different side moldings, which ran along the bodyside sculpturing. The usual red-filled SS letters on the rear fenders did not use the Impala emblem. The SS models got the aluminized taillight panel insert and additional SS identification on the right side of the trunk. The new wheel covers did not have the nonfunctional knock-off spinners. Available only as a convertible or Sport Coupe, the SS was offered with the same engines as 1963, including the top of the line 409, except the 427ci 2x4bbl 430hp V-8 was dropped. But the introduction of the Pontiac GTO would steal the Impala SS thunder as buyers began to shift over to smaller, lighter cars that could offer similar performance for less money than the full size car.
The Impala was completely redesigned for 1965 and featured a more streamlined look, rather than the boxy look of previous years. The new Impala was advertised as having “foam-cushioned seats, deep twist carpeting, new engines and transmissions and Wide-stance handling”. The Sport Coupe had a new fastback roofline. (Impala SS engine options included the 230ci 140hp I-6, 283ci 195hp V-8, 327ci 250 V-8, 327ci 300 V-8, 396ci 4 bbl 325 V-8, 396ci 4 bbl 425 V-8, 409ci 4 bbl 340hp V-8 and the 409ci 4 bbl 400hp V-8.) In February, the mighty 409 was phased out and was replaced by the Mark IV 396 cid V8, which would power Chevrolets for the rest of the '60s. The new 396 could be mated to a new automatic transmission, the Turbo Hydra-matic 350. The 396 was a direct descendant of the "Daytona Mystery Engine" The 409s and 396s were available in all Impalas, including four door sedans and station wagons, but the Impala SS continued as a separate series. 1965 also saw the introduction of the Caprice option on the Impala and came standard with a V8. The '65 model also featured round triple taillights - a classic Impala styling cue. The frame was changed from the old X-member to a new “full-perimeter” type that supported the new larger bodies, provided superior strength and enhanced quietness and ride comfort. Full-size SS sales would never again be so high. Gasoline was still relatively cheap, and the rate of passenger car travel continued to grow, with statistics showing a 21 percent increase from 1960 to 1965. The boom of the '50s continued into the '60s, with the Chevrolet Impala leading the way.
By 1966, the Impala SS was beginning to lose its luster. The Caprice became the new top of the line Chevrolet, stealing the Impala's luxury image while the SS was becoming more of an appearance package rather than a performance one. (Impala SS engine options included the 250ci 155hp I-6, 283ci 195hp V-8, 283ci 4 bbl 220hp V-8, 327ci 4 bbl 275hp V-8, 396ci 4 bbl 325 V-8, 427ci 4 bbl 390hp V-8 and the 427ci 4 bbl 425hp V-8.) The Impala also lost its signature six round taillights, which had been an Impala trademark since 1958. New large rectangular ones replaced them along with a more massively styled front end. The Mark IV 396 continued, but a larger 427 version was introduced. It was rated at 390 bhp, while the "special performance" version was rated at 425 bhp due to solid lifters, four-barrel carb with aluminum manifold and heavy duty four bolt main block. The 427 was available with a special performance, extra rugged, extra noisy, four speed manual transmission, called the "rock-crusher." The Impala SS sales were down by more than 50% to 119,312 due to lost sales to the Caprice and smaller midsize performance muscle cars.
The 1967 Impala was again restyled, looking longer and heavier, with the fastback roof design being even more pronounced. (Impala SS engine options included the 250ci 155hp I-6, 283ci 195hp V-8, 327ci 4 bbl 275hp V-8, 396ci 4 bbl 325 V-8 and the 427ci 4 bbl 385hp V-8.) On the SS models, the new front grille featured blacked-out horizontal strips, and on the rear was a black panel insert between the taillights. The SS identification could be found on the grille, trunk lid and each front fender. In the interior the SS identification was limited to an SS emblem on the glovebox door. The Impala SS sales continued to fall as buyers increasingly turned away from full-size performance. The SS began to look more and more like the standard Impala, with only a black accented lower body sill and bright fender moldings on the SS. The SS 427 came with a unique domed hood with three simulated air ducts, large SS 427 emblems in the center of the grille and on the rear panel between the taillights, HD suspension components and Red Line 8.25 x 14 tires on 14” x 6” rims. The Impala also had a host of new safety and convenience features, including a dual master cylinder brake system, an energy absorbing steering column, and an ignition switch illuminated by the first use of fiber optics technology to appear in a Chevrolet.
In 1968 due to the increased emphasis on luxury, the Impala SS reverted back to an option package (RPO Z03 at $179), and was ordered on only 38,210 out of 710,900 Impalas. (Impala SS engine options included the 250ci 155hp I-6, 307ci 200hp V-8, 327ci 4 bbl 250hp V-8, 327ci 4 bbl 275hp V-8, 396ci 4 bbl 325 V-8, 427ci 4 bbl 385hp V-8 and the 427ci 4 bbl 425hp V-8.) The SS option was now available on three models, the convertible, the Sport Coupe (hardtop coupe), and the Custom Coupe. Both the 396 and 427 engines continued, despite continued falling sales. The SS 427 package continued as RPO Z24, with the 385hp 427ci engine, but a 425hp 427ci was optionally available. This was the L72 427 with the big port heads, aluminum intake and Holley 780 cfm combination, 11.0:1 compression and a solid-lifter camshaft. In addition to the minor facelift on the 1968 Impala, new styling features included hideaway windshield wipers and front and rear side-mounted marker lights, which were federally mandated. On the rear, the Impala returned to the three-per-side taillight motif, but these were mounted within the new bumper.
The year 1969 marked the end of the Super Sport Impala. Due to poor sales, Chevrolet eliminated the SS option on all full size cars except one, the Impala SS 427. (Impala SS included only the 427ci 4 bbl 390hp V-8 or the 427ci 4 bbl 425hp V-8.) The 1969 Impala SS option ($422) featured new pontoon-bulge fender lines and new "full door glass" which eliminated the vent windows. The SS identification was limited to an SS emblem on the steering wheel in the interior. Exterior identification was limited to a blacked-out grille with the SS lettering in the center, and fender and trunk lid emblems. Only 2,455 copies of the Impala SS 427 were sold, which ensured that this would be the last year of the famed Impala SS. The Impala line would continue, sporting the new 454 cid V8 engine for 1970 and surviving well into the late 1970s. But the Impala would never recapture its performance image and became just a luxury full-size car. But in retrospect, an impressive 918,000 Impala SS were manufactured, a true testament to its significance.
Impala ruled America's roads during the '60s. Impala embodied the Chevrolet "magic formula" at its very best, and customers gobbled them up, with 7.8 million sold from '60 to '69. The Chevrolet Impala was America's favorite car at the beginning of the '60s, at the end, and during every year in between. "Never in recent history has the demand for our top models equipped with a maximum of options been as strong," said then-Chevrolet general manager Semon "Bunkie" Knudsen.
To keep up with demand, Impala evolved at a frenetic rate, introducing all-new designs in '61 and '65, and styling changes every year of the '60s. Impala’s landmark year was 1965 when Chevrolet sold more than one million Impalas in that year alone. A record no other nameplate has ever topped. Suddenly, the Impala name almost seemed prophetic - the car named for an animal capable of extraordinary leaps had bounded from nonexistence to history's top seller in just six years.
In 1970 the Impala received the usual facelift which resulted in minor changes to the front, rear and sides. The front bumper was replaced with a split grille theme. The leading edge of the front fenders was squared off so they no longer played a dominant role in the front end design. The three distinctive taillights were on each side and once again recessed within the bumper. A new big block was introduced in 1970- the 454. Two variants were available: one rated at 345hp and the other at 390hp. Next in line was the 300hp 350ci and the 265hp 400ci. The 307 was the basic mill. If you ordered the Impala custom coupe, it was outfitted with front disc brakes, but other Impalas received drum brakes on all four wheels. Prices ranged from $3,021-$3,377. Weights were approximately 3,641-3,871 lbs.
The 1971 Impala received small changes in outward appearance. The emphasis continued to be on luxury and the resemblance to the Cadillac remained a fundamental connection for the Impala image. The Impala became as big as they’d ever be with a 1971 redesign introducing round-sided “fuselage” styling on a new 121.5” wheelbase.
In '72, Impala all-time sales topped the 10 million mark, extending its lead as the best-selling full-size car in automotive history . . . more than double the sales of the next nearest competitor at the time, the Ford Galaxie. Design changes for 1972 were minimal. Impala's length was stretched to 219.9 inches, making it the longest Impala yet and still the best-selling full-size car in the U.S. to date. Impala offered enhanced comfort, roominess, safety, improved ride and handling, and a list of options that buyers a decade earlier may never have dreamed of . . . such as air conditioning with automatic temperature control, electric door locks and an AM/FM stereo with tape player. It should be noted when making performance comparisons between the 1972 and newer Impalas to the 1971 and older Impalas that there were new methods to determine horsepower ratings. The 1972 and newer cars were rated on net horsepower rather than gross horsepower, which resulted in lower numbers. However, the 365hp 454ci engine from 1971 delivered the same real world performance as the 270hp 454ci from 1972.
In 1973, Impala's success continued, again outselling every other car in the country. Tightening government regulations and a fuel crisis, however, would change the automobile industry - and the Impala - forever. The impact of the 1973 oil embargo on the industry was dramatic. Gasoline prices doubled between 1973 and 1979. Industry car sales plummeted 20 percent between '73 and '74, and for the first time in recent history, annual passenger car travel in the U.S. actually went down. The turmoil left Americans groping for more fuel-efficient transportation, and the trend in popularity toward lighter, smaller cars was here to stay. Changes to the Impala from 1972 to 1976 were minimal. Performance orientation was sidetracked while issues such as pollution control and safety took center stage. And as the popularity of small cars and fuel economy increased, the Impala looked increasingly out of place and out of touch with what most people wanted. Engines included the standard 350 ci 145 bhp V8 as well as the optional engines.
The 1974 Impala got a more squarish grille and a rear end reprofiled to accept the newly required 5-mph bumper. In 1974 Chevrolet introduced a limited-edition “Spirit of America” Impala painted red and white with blue accent stripes and special wheels. It was a failed attempt to create an exclusive Impala for the upcoming bicentennial.
The 1975 Impala four-door Sport Sedan got the same new roofline as its Caprice counterpart, but had a different grille insert, no rear fender skirts, and a somewhat less opulent interior. In 1975 a landau coupe was introduced with a thick padded roof over the rear portion of the passenger compartment. In its first season less than 2500 landau coupes were sold. After several unsuccessful years this model was dropped.
The 1976 kept the 1975 “hand–me-down” front end and finished out the last year of the large size Impala before the complete redesign in 1977. New front end styling and engine/brake refinements were included. The Sport Coupe was also dropped for 1976 and the Impala Sedan was added. The Impala refined its “swept back” front end look with new round quad headlights (as on the 1975 Caprice). At the rear were triple-unit wraparound taillights.
And, of course, anything built after the mid Seventies was crap, so I'll just stop there.