While muscle cars literally went out of fashion in 1970, it was too big a thing to just stop. Developing new cars and engines takes 3 or more years of engineering, so products that had entered the development pipeline in 1967 were just hitting the market in 1970, including:
- Chrysler had just rolled out their new Dodge Challenger and Plymouth Barracuda pony-cars, based on a shortened version of their mid-size chassis. These two corporate twins finally had the mean, modern styling to compete with the Mustang and Camaro, and an engine bay that made the Hemi look small. OK, not small, but average.
- Plymouth had restyled their boxy Valiant compact into the swoopier Duster model and offered it with the muscular new 340 inch small-block V8.
- Ford's had just launched two new engines families, represented by the 351 inch Cleveland small-block and the 429 inch big-block V8.
- Ford's Fairlane would be renamed the Torino and given swoopier (more Chevelle-like) styling.
- GM had introduced the first major restyling of the Camaro, with a high-performance version of the trusty 350 inch Chevy small-block V8 that provided big-block power-levels without the big-block's weight and thirst for 100 octane premium. Much like the Cleveland-motored Mustang, this was one of the best performing Camaros ever.
- Across GM, the various big-block engines had been stretched to 7.5 liters (454 or 455 cubic inches), and these big big-blocks would be offered in the various GM mid-size models (Chevelle, GTO, Cutlass/442 and Skylark/GranSport) for a few more model years.
In 1971 Ford would launch a new much larger Mustang that was more of a cruiser than a sportscar. This new plus-sized Mustang was influenced by Bunkie Knudsen, the father of the GTO, who Henry Ford II had wooed away from GM. Knudsen had revitalized Pontiac with a big-car, big-engine strategy and he would try to do the same at Ford: the new Mustang was offered with the new 429 V8 (without the special NASCAR inspired Boss cylinder heads) and a still fairly stout version of the 351 Cleveland, but the car had lost its athletic looks and engine output would drop over the next few model years.
In 1972 Ford's racy new Torino mid-size would morph into the Gran Torino, another plus-sized redesign that included a change to body-on-frame construction for improved ride and crash resistance, and would offer the same 351 and 429 engines as the Mustang, and later would offer the 429's big brother - the 460 V8 - but by then it wasn't much of a performance motor. The performance oriented 351 Cleveland (with four-barrel carb) would hang on until 1974, but even it was fairly ordinary by 1960s standards.
GMs 7 mid-size cars would hang on largely unchanged through 1972, including the new 7.5 liter engines, although selling in ever smaller numbers. The GTO name plate would be appear briefly on the 1973 Grand Am (a heavily restyled mid-size Pontiac) and on the 1974 Ventura (Pontiac's clone of the Nova) before disappearing into history.
The new Chevy Camaro and Pontiac Firebird would soldier on throughout the 1970s, although again every year would bring less powerful engines. Pontiac would make one last gasp in 1973 with a Super Duty version of their 455 V8 that would have been right at home in the 1960s, but it sold in limited numbers and would not be offered again.
Chrysler would offer the Hemi through the 1971 model year and keep selling the restyled Challenger and Cuda until 1974, but would take the same path as Ford and GM, de-tuning engines every year. Plymouth would field a RoadRunner package on the 1976 Volare (a re-designed Valiant), but it was mostly a decal-package; the real muscle was gone by 1973.
Sealing the muscle car's fate was something automakers could never imagine and plan for in 1967 or even 1970: the OPEC engineered oil boycott of 1973. While the politics and economics of the boycott are complicated, the end result was simple: in October of 1973, just as the new 1974 model cars were hitting the dealerships, US gasoline prices tripled, and thanks largely to panic buying there were actual shortages - gas stations simply ran out. Suddenly no one wanted the big safe cars Detroit imagined they would be selling through out the 1970s, and four-barrel-carburetor became a dirty word in auto showrooms and used car lots.
Even worse, Detroit had no efficient full-size cars in their development pipeline. Ford had their new sub-compact Pinto and Chevy had the Vega, but these were cheap, tiny (and slow) little cars meant to compete with the VW Beetle and the newly arriving Japanese imports. If you wanted a reasonably fuel-efficient car that you could pack mom, dad and a couple kids into, the only choices were the 6 cylinder Dodge Dart and Ford Maverick, which were really crude little cars that dated back to the early 1960s. To be sure, they were reliable transportation, but nobody lusted after a Maverick.
Somehow the Big 3 had to make 4000+ pound Ford LTDs, Chevy Caprices and Dodge Polaras easy on gas. The only short term solution was to stuff smaller engines and steeper rear-end gear ratios into these land yachts, and hope that since all the other cars coming from Detroit were just as dog-slow no one notice. That strategy might have worked, except that the Japanese and Europeans had been dealing with expensive gas and safety standards for years; they had already developed space efficient, light-weight and reasonably safe cars that gave reasonable performance with 4 and 6 cylinder engines that were half the size of even a small American V8. Cars like the Toyota Corolla, Datsun 510, BMW 2002 and Saab 99, while not huge sellers would slowly build a following in the US and would show the direction US cars would take.
Perhaps the low point of the times was the "all new" Mustang II introduced in 1974. The new Mustang had a back-to-basics strategy championed by Lee Iaccoca, and at least on paper appeared to be a first step towards building an American import-fighter: the car was smaller and lighter than the previous generation (1971-1973) Mustang. For the first time there was a true hatchback, a practical feature America was learning to love in the imports. The styling was inspired by the first generation Mustang, but it lacked the chrome of the original, using plastic front and rear bumpers to meet the new 5mph impact regulations. Power was provided by a 2.3 liter 4 cylinder or 2.8 liter V6.
With gas prices spiking, the new small-motor Mustangs sold well, but they lacked the power and sporty handling of the imports. While seemingly a match for the latest sporty cars from Japan (Datsun's Z-cars and Toyota's Celica), the Mustang betrayed its Pinto roots when pushed hard. After the first year, Ford would offer a (fairly tame) 302 V8 in the new Mustang, which helped, but not nearly enough. Chevy was still offering the 350 small block V8 in the Camaro, and Pontiac the 400 big-block in the Firebird, and while these were heavily de-tuned engines there were lots of performance parts available in the aftermarket. The Mustang would become the poster-boy for the emasculated performance car.
Of course it wasn't that American automakers couldn't build the same kinds of light, sporty, reliable and fuel-efficient cars that the Japanese and Europeans were building; it was just that they had never had to before. It was a change - not just in their products but in their very business model - that would take another 5 years just to get started. In 1978 Chevy would roll out its new Malibu and Ford the new Fairmont; both reasonably modern small mid-size cars. Not great cars, but respectable first efforts.
To help pay for developing these new cars (and more new models still in the pipeline) Ford and GM would limit changes to the rest of their lineups (no more yearly updates to the chrome strips and upholstery). Chrysler - always the smallest of the big 3 - didn't have the cash for an all new car and would struggle to survive going into the 1980s.
By 1978 the Mustang II was 5 years old and really showing its age. For 1979 Ford would return to the original formula for the Mustang, bolting a sporty body to a shortened version of the new Fairmont's chassis. Ford would dabble with a turbo-charged 4 cylinder in this all new Mustang, but would also tool up a small-block V8 option. The new Pony's first few years weren't very memorable - in 1980 and 81 the top engine option was an anemic 255 inch V8 making just 120 (net) horsepower - but by 1982 the world oil market had stabilized and Ford took a chance on a performance option for the Mustang: a 302 with bigger valves and a hotter camshaft sourced from Ford's bottomless parts bins, kicking out 157 horsepower in a car weighing just 2600 pounds.
No one would confuse this new Mustang GT for a Cobra Jet or even a Boss 302 from 1969, but it was at least in the same league as the first 289 V8 powered Mustangs. And with its light weight and an over-drive 4-speed transmission, the V8 still gave respectable mileage. After most of a decade where high-performance meant a high-revving 4 cylinder, America would rediscover the wonderful instant-on power available from even a small-block V8, and it was love all over again. If you could swing the insurance payments, you ran out and bought a V8 Mustang before Ford came to their senses.
Finally the Mustang could hold its own with the foreign competition, and GM had no choice but to upgrade its aging Camaro to keep up. In 1983 Chevy would roll out an all new Camaro and Firebird, with their own high-performance tuned small-block V8. Ford would up the ante with an honest-to-God Holley four-barrel on the 302, pushing horsepower up to 175 and kicking off a round of tit-for-tat one-upmanship between Ford and GM that continues right up to today. 1983 was like 1964 all over again.
And - no surprise - it looks like we'll need at least 10 more paragraphs to wrap things up. Stay tuned...