Nineteen seventy was a watershed year in the history of the American muscle car. Most would agree that the muscle era hit its apogee in 1970, when too much performance was not enough and user friendliness was shoved aside by an antisocial attitude; vying for the top of the pops was Chevrolet's Chevelle SS 454. The SS 454 carried Chevy's intermediate performance banner, wrapping a lean, butch exterior around serious big-block horsepower and igniting a reverence that burns strong more than 30 years later. With its ample and inexpensive parts supply, ease of restoration and classic all-American appeal, the 1970-1972 Chevelle SS 454 is the muscle car that nearly everyone with gasoline in their veins wants in their garage.
Chevrolet had restyled their mid-size Chevelle lineup for 1970, taking a highly detailed car and simplifying it; the new car's squared-off C-pillar replaced the previous model's dramatically curved one, and subtly flared fenders and bobbed front and rear ends gave the new car a more menacing, serious look that was both contemporary and timeless. The Super Sport package, Chevelle's highest performance option, was again available in the hardtop Sport Coupe ($3,497) and convertible ($3,697) body styles. The 1970 SS carried a number of distinctive styling cues, including quad headlamps in squared bezels, a two-part grille separated by a body-colored bar, and rectangular taillamps set in a chrome bumper that carried black inserts. A domed hood was also standard on the SS models, which included the previous top-dog SS 396 and the new boss, the SS 454.
A special option package, known internally as Z15, cost $503.45 in 1970 and would transform a plain-Jane Malibu into the fabled SS 454. This package included a 454-cu.in., 360hp Turbo-Jet V-8 (known as the LS5) with chrome accents, a heavy-duty suspension, SS wheels, power front disc brakes, dual exhausts with chrome tips, wheel arch moldings, a black grille and a chrome rear bumper with black inserts. Various SS badges also adorned the car, inside and out. For the extremists for whom 360hp was not enough, or for those who wanted to taunt overconfident Hemi-powered Mopar drivers, the LS6 option, costing a mere $263.30, brought the ultimate 450hp V-8. Extra street cred could be bought with the $147.45 ZL2 option, a.k.a. the Cowl-Induction hood package; this sport-striped hood, which was secured with pins, had a vacuum-operated flap that ducted cold air to the carburetor when the accelerator was floored. According to contemporary sources, a 450hp LS6-equipped SS 454 could run 0-60 mph in 6.1 seconds and cover the quarter mile in 13.44 at 108 mph.
A number of detail changes helped usher the Chevelle SS 454 into the 1971 model year. Last year's optional hood pins were standardized, the grille was modified to lose its painted center stripe, and new front fender-mounted wraparound turn signals replaced those in the bumper. While the front swapped its twin round headlamps for singles, the rear traded its single taillamps for twin round replacements, mounted in a now all-chrome rear bumper. The 14 x 7-inch SS 5-spoke wheel of 1969 and 1970 was replaced by a 15 x 7 wide-spoke wheel that wore a dark gray finish and bright trim ring and was shared with the new Camaro. The interior was virtually unchanged save for new patterns on the Madrid grain vinyl seats, which featured Elk grain center inserts. In 1972, exterior changes to the Sport Coupe and convertible were limited to a widened grille that reached the thinner headlamp bezels, single-unit turn wraparound signals and a short piece of door-rub strip molding.
Although the Chevelle family of cars was one of Chevrolet's best sellers in the early 1970s, the hairy and expensive Super Sport 454s were understandably rare. A mere 3,733 were built in 1970; 19,992 left dealer lots in 1971; and in 1972, 5,333 were sold. Because these are among the hottest muscle cars ever built and, depending on engine and options, can command serious money, some nefarious folks have built SS 454 clones with matching forged documents, cowl tags and protect-o-plates; every effort should be made to authenticate LS6-equipped cars.
Engines:
What really makes a Chevelle SS 454 special? Need we ask-the engines! In 1970, this model could be fitted with one of two 454-cu.in. (7.4-liter!) V-8s. Buyers who chose code RPO LS5 got the "basic" engine, if a 360hp V-8 could be called that. The LS5, which featured a new, larger combustion chamber design, used the same cast-iron heads as the SS 396's 350hp engine; with hydraulic valve lifters, a 4.25 x 4.00 bore and stroke, a 10.25:1 compression ratio, 4-bbl. Rochester 4MV carburetor and dual exhausts, the LS5 made the aforementioned 360hp at 4,400 rpm and 500 lbs.-ft. of torque at 3,200 rpm. The holy grail of Chevelle engines in 1970 was certainly RPO LS6; this V-8 shared its bore and stroke with the LS5, but upped the ante with unique heads that used 1.88-inch exhaust valves and 2.19-inch intake valves, solid valve lifters, a high-performance camshaft, 11.25 compression and a 4-bbl. Holley 4557 or 4150 carburetor. It made an underrated 450hp at 5,600 rpm and 500 lbs.-ft. of torque at 3,600 rpm, some of the most impressive numbers in the industry, but its solid lifters made it more maintenance intensive than its hydraulic lifter-equipped brethren.
In 1971, Chevrolet lowered the compression ratios in all their engines and switched their power ratings from gross to net figures, which signaled the beginning of the end of the halcyon days of muscle power. With its new 8.5 compression, the LS5 engine made a gross-rated 365hp at 4,800 rpm and 465 lbs.-ft. of torque at 3,200 rpm; the net power ratings for the same engine were 285hp at 4,000 rpm and 390 lbs.-ft. of torque at 3,200 rpm. The LS6 used a 9.0:1 compression ratio to make 425hp at 5,600 rpm and 475 lbs.-ft. of torque at 4,000 rpm, gross, while the net figures were a bit tamer: 325hp at 5,600 rpm and 390 lbs.-ft. of torque at 3,600 rpm.
The performance picture, while still impressive compared to what would be available in a couple of years, was bleaker for 1972 because the hot LS6 option had been cancelled in May 1971. The only engine available in Chevelle SS 454s was the LS5, which ran 8.5-compression and retained its 4-bbl. Rochester carb and dual exhausts. It made a now net-rated 270hp at 4,000 rpm and 390 lbs.-ft. of torque at 3,200 rpm; sadly, this big-block SS was not sold in California in 1972, as it wouldn't meet their stricter emissions standards. All was not lost, though-enterprising performance lovers could purchase the parts to turn their LS5 engines into LS6s at the parts counter of their local Chevrolet dealerships. Today, the market for Chevrolet engine parts is booming, and these sturdy V-8s are among the easiest to find mechanical parts for.
Transmissions:
The standard transmission on the 1970 SS 454 was the Muncie M21 close-ratio 4-speed manual with an 11-inch clutch. For 1971 and 1972, the stock 4-speed was replaced with the heavy-duty M22 unit. The M40 three-speed Turbo Hydra-Matic was optional with both engines in 1970 and '71, and with the sole remaining 454 in 1972. They are known for their reliability and strength, but if you find a car with a tired unit, don't worry-service parts and performance upgrades are easy to have done.
Differentials:
The stock differential in 1970 Chevelle SS 454s was an open hypoid 12-bolt unit with a 3.31:1 ratio, although a Positraction limited-slip unit with the same ratio was optional with all transmission choices. A dealer-installed performance option for that year was a Positraction with 4.10 gears. In 1971, the ratio choices were the same, but the 4.10s disappeared for 1972. All Chevy differentials are notably hearty, but the new Chevelle owner who wants to race his SS 454 might consider exchanging an open rear for a Positraction unit with different gearing for extra squirt.
Suspension:
As was standard GM A-body practice in its day, the Chevelle SS 454 used an independent front suspension and a live axle with a four-link suspension setup in the rear. The front had upper and lower control arms with ball joints, heavy-duty coil springs, AC Delco shocks and a standard 1.25-inch-diameter anti-roll bar. The rear used upper and lower control arms, coil springs and Delco shocks. All stock suspension parts are being reproduced to encourage factory-correct restorations, but NOS date-coded spiral-tube shocks are getting rare and pricey.
Brakes:
Power assist for the front-disc/rear-drum system was a part of the SS 454 package for all three years, which was a notable upgrade from the all-drum system. The discs were 10.94 inches in diameter and used single-piston calipers, while the rear drums measured 9.5 x 2 inches. Famous GM parts interchangeability makes brake upgrades or component swaps a painless proposal.
Chassis:
All SS 454 models rode on a 112-inch wheelbase that was shorter than the wheelbases of the sedan and station wagon models; their perimeter frames carried welded front and rear cross-members. Sport coupes rode on an open-rail frame, while convertibles had boxed side rails for greater stiffness. It's smart to put a prospective project car on a lift and check the frame for rust, especially noting the body-mounting frame braces and the differential mountings in the vicinity of the rear suspension control arms-repair or replacement is straightforward, but it's time consuming and expensive.
Body:
Like their GM A-Body siblings, the Chevelle SS 454 Sports Coupe and convertible are solidly built but aren't impervious to rust. Cars from northern regions tend to exhibit rust in the lower doors, lower fenders and quarter panels, while the fill panel between the rear window and trunk lid collects water and rusts through. As benefiting the Chevelle's immense popularity, a dizzying array of reproduction full or partial replacement body panels can offer even Swiss cheese-looking SS 454s a new lease on life, although from a financial standpoint, this is never the most sensible restoration plan. Buy dry and your checkbook won't make you cry!
Interiors:
Roncina cloth and Madrid/Elk vinyl seating was standard on closed, bench-seated 1970-72 454 SS models, and an all-vinyl interior, standard on convertibles, was available in Sport Coupes with benches or optional Strato-buckets. Interchangeable door panels on all Chevelle models from 1970-72 differed only with SS-nameplate trims. Glove compartment doors were interchangeable with the contemporary Monte Carlo, which also shared its standard instrumentation; those could be upgraded with a tacho and accessory gauges to replace the standard warning lamps. New carpeting, package shelves, door panels, seat foams and dashboard units are among the many interior products that are being reproduced today.
Reproduction Parts:
If you need a bumper, front fender brace, plastic front inner fender well, tie rod dust boot, molding set, windshield or steering column sponge seal for your 1970-1972 Chevelle SS 454, you can find it from a great number of sources, and at reasonable prices. The number of high-quality reproduction parts for these cars almost makes scrounging through boneyards and swap meets a thing of the past. The major engine and trim pieces that make up the SS package are all being reproduced, along with striping and stencil kits to give a freshly repainted car back its bruiser-cruiser attitude. Brian Stiscia, the owner of our feature car, warned that he had a difficult time locating some smog equipment that was originally used on the 454-cu.in. V-8 in 1970, as it isn't being reproduced. He also said that the outside mirror, which had a unique mounting style, was tough to come by. While most chrome trim and interior parts are shared with other Chevelles and Malibus, many fittings and under-the-surface components are shared with other A-Body cars; so don't forget to check Buick Skylark/GSs, Olds Cutlass/4-4-2 and Pontiac Le Mans/GTOs if you simply can't find a new or NOS part.
Performance Parts:
The Chevelle is very amenable to performance upgrades, and because of its great popularity, a number of high-profile suppliers sell excellent quality parts to boost the already impressive horsepower and torque figures. From big-cfm carbs and dual-plane alloy intakes to high-voltage ignitions and free-flowing exhausts, it's all available for the taking. Other readily available components include heavy-duty transmissions, competition torque converters and clutches, camshafts, hardened pushrods and aluminum cylinder heads. If your SS is a shell, or its 454 is beyond repair, GM Performance Parts offers complete big-block crate engines that are ready to bolt in, making over 500hp. Here, Viper Viper Viper...
Chassis Upgrades
If you enjoy driving fast around corners as much as you like driving fast in a straight line, you can turn an SS 454 into a willing dance partner. Start with upgraded urethane suspension bushings and adjustable tie rod ends from Moog, then move on to Global West negative-roll front control arms, boxed lower-rear control arms, lowered coil springs and traction bars. Don't forget Bilstein, Koni or KYB gas-charged shocks and a bolt-on rear stabilizer bar. Mount a set of modern high-performance radials on widened SS rims from Wheel Vintiques or lightweight alloy wheels for the ultimate in grip. Braking power, which was never the A-body's forte, is easily amended with off-the-shelf GM parts like F-body brake rotors mounted on B-body spindles. Retrofitting GM or aftermarket discs to the rear is made easy through a number of comprehensive conversion kits, including those from Ground Up and Stainless Steel Brakes. While most SS 454s were almost single-minded race cars straight from the factory, with the help of modern technology, they can be made into well-rounded (dare we say practical?) cars with time-warping performance and an aggressive swagger that is nearly unmatched among classic muscle cars.
Owner's View:
"I've always been a Chevelle nut, and I love Chevys through and through," says Brian Stiscia, of Gardner, New York, the owner of our Cortez Silver 1970 LS6. "I previously had a Fathom Blue 1970 LS6, though that one wasn't done to the magnitude of this car. I owned it when it was basically still affordable, before prices went through the roof." Brian bought his silver beauty from Arizona, partially restored, and finished it to exacting factory standards. "I wanted to make this car 100% perfect, down to the nuts and bolts, without a clip or tie wrap out of place. I have its complete history, and I've talked with all the previous owners-all the car's numbers match and the date codes are correct. It represents a lot of blood, sweat and tears." Because of its show-quality restoration and factory correctness, Brian doesn't run it as hard as his previous car: "The other car didn't have its original block, but the engine was ported and polished and it would twist your head off, it was so violent. This car runs good, but with the smog equipment and factory setup, it can't breathe as well. Unfortunately, I get a little paranoid driving it. But I love seeing people's reactions," he smiles-"They're stunned. They pay attention to the details, and that's what this car is all about." How does this SS 454 fit in the ever-increasing muscle car market? "Not a lot of average-Joe people like me can afford to build a car like this anymore," Brian says. "I know how lucky I am to own it, and although I get offers all the time, I don't think I could part with it!"
Values:
1970 LS6:
1971 LS6:
1972 LS6:
Parts Prices
Bumper $210
Door Panels (Pre-assembled set) $320
Grille Assembly $150
Grille (NOS) $400
Gas Tank $190
Hood $325
Fender $280
Fender (NOS) $900
Core Support $130
Rocker Panel $90
Rocker Panel (NOS) $250
Radiator Shroud $120
Seat Covers $220
"454" Grille Emblem $50
Fuel Pump $45
Exhaust System, aluminized $350
Exhaust System, stainless $1,000
Engine Harness $125
454/425HP Crate Engine $5,000
Club Scene:
American Chevelle Enthusiasts Society
615-773-2237
Dues: $40/year; Membership: 6,000
www.chevelles.com/aces/index.shtml
Classic Chevy International
800-456-1957
Dues: $39/year; Membership: 25,000
www.classicchevyworld.com
Late Great Chevys
800-683-1961
Dues: $40/year; Membership: 12,500
www.lategreatchevy.com
Vintage Chevrolet Club of America
626-963-2438
Dues:$30/year; Membership: 6,000
www.vcca.org
