The 1971-73 Ford Mustang has been widely criticized for growing too big and fat. However, Ford didn’t act in isolation — all of the pony cars saw meaningful increases in size and weight when they were redesigned in the early-70s. Indeed, the Pontiac Firebird was one of the biggest offenders. Model for model, the second-generation Firebird became the heaviest pony car.
The 1971 Mustang added 300 pounds from a comparably equipped 1967 model, but it was still a good 260 pounds lighter than the Firebird, whose redesigned body was introduced in the middle of the 1970 model year.
The above table only shows weights for six-cylinder models. The top-end Firebird Trans Am V8 weighed even more: 3,575 pounds. That was heavier than a Dodge Challenger R/T (80 pounds), Mercury Cougar XR-7 (260 pounds) and AMC Javelin AMX (330 pounds).
Like the rest of the pony cars, the Firebird got heavier partly because it grew in length and width. In addition, the so-called F-body the Firebird shared with the Chevrolet Camaro was also weighed down by new features such as exceptionally long doors, which eliminated quarter windows between the B- and C-pillars.
General Motors’ designers deserve credit for visually minimizing the F-body’s bigger size. This was partly accomplished by unusually curvaceous fender shapes, a gently tapered fastback roofline and a lithe rear end.
This was in stark contrast to Ford designers, who emphasized slab sides, heavy creases and kammback rear ends. The unhappy result was that the Mustang and Cougar looked even more ponderous than they actually were. The most extreme example was the Mustang fastback, with its almost horizontal backlight and a rear end reminiscent of an ice cream truck.
The F-body also hid its width better than Chrysler’s pony car twins. This is particularly apparent in hood treatments. Whereas the Challenger and Plymouth Barracuda both adopted flat hoods and heavily horizontal grilles that accentuated each car’s width, both the Firebird and Camaro included Jaguaresque curves around their single headlights and radiator-style grilles.
I’d argue that the second-generation Firebird and Camaro were the best executed designs in the history of each of these nameplates. Unfortunately, an automotive designer can do only so much with an obese platform. That raises an interesting question: What if one applied the Firebird’s terrific styling to a platform that was similar in size and weight to the original Mustang?
It wouldn’t have taken much to fix the Firebird
The photo below shows the 1970 Firebird from one of its more flattering angles. Nevertheless, the car does not have the lean proportions of a European sporty coupe of that era. Both the front and rear overhangs are too long. Meanwhile, the greenhouse is so low that it has a turret-topped quality, which is exacerbated by the unusually upright A-pillar and an overly long door.
The photoshopped Firebird below addresses all of these issues. The wheelbase ahead of the front wheels is cut by four inches, and both the front and rear overhangs are each trimmed by around two inches. You can’t see it in this side view, but the width is reduced by around 3.5 inches. Meanwhile, the greenhouse is raised roughly an inch and the windshield is given a sharper angle without getting rid of its lovely curvature. Adding quarter windows gives the Firebird an airier and more rounded look.
Pruning the Firebird’s dimensions should have resulted in a corresponding reduction in weight. Even the original Firebird and Camaro were much heavier than the Mustang, so some serious work was needed in this department. If engineers could have reduced the Firebird’s weight by around 300 pounds, it could have been a terrific match with Pontiac’s overhead-cam six, which had been discontinued after 1969.
The OHC six represented only 20 percent of the Firebird’s 1967-68 sales. However, buyer interest might have increased in the early-70s, when a recession led to soaring sales for compact two-door coupes with good fuel economy . . . at the same time that sales tanked for all of those bigger, glitzier and more powerful pony cars. This may help explain why Ford executive Lee Iacocca reportedly stated, “The Mustang market never left us, we left it.”
Pony car sales went down as the bloat went up
The graph below shows how every pony car except for the Mustang saw its output fall below 100,000 units by 1972. The Firebird managed to maintain a fourth-place standing behind the Mustang, Camaro and Cougar, but output fell to less than 30,000 in 1972 — and from 1970-73 averaged under 45,000 per year. Compare that to 1968, when production peaked at over 106,000 units and averaged roughly 92,000 per year between 1967-69.
American automakers must have been nonplussed to see how their costly pony car redesigns were selling so poorly that some may have never turned a profit. This was happening at the same time when the Plymouth Duster — a modest redesign of the aging Valiant — was selling more than 224,000 units per year between 1970-73.
While a goodly portion of those Dusters were strippo models, you could option one to levels approaching that of the 1967-69 Barracuda. A key reason why the 1970-73 Barracuda was one of the worst-selling pony cars could have been because its compact counterpart was arguably a better deal.
Or consider the Ford Maverick. When it was introduced in the spring of 1969, the car was positioned as a bargain-basement import fighter. The Maverick coupe was essentially a shortened and decontented 1969 Mustang. However, the Maverick probably did not cannibalize many Mustang sales because it was such a bare-bones design even with its sporty trim package, the oddly-named Grabber.
That said, Ford sold far more Mavericks than Mustangs during 1970-73: Roughly one million units versus 609,000 units, respectively. Might the Mustang have done better if it hadn’t bloated out so much? Here’s one indicator: Even though 1970 sales were depressed by a recession and an aging design that was overshadowed by GM’s new F-body, the Mustang still sold substantially better than in 1971-73. Bigger didn’t turn out to be a better.
The ‘Sexy European’ upstages American pony cars
This did not fit on the above graph, but another warning sign was the early-70s Mercury Capri, which was Ford of Europe’s interpretation of an American pony car. In 1970, the first year the Capri was imported through Lincoln-Mercury dealers, sales were modest — roughly 17,300 units. However, by 1973 sales had soared to 113,100. Tellingly, in 1972-73 the Capri handily outsold every American pony car except for the Mustang. That was despite an escalating price tag that, by 1973, matched its American competitors even though the Capri was much smaller.
For roughly the same price of a 1973 Capri V6 ($3,261), you could get “a lot more car for your money” — a Firebird V8 in mid-range Esprit or Formula trim. Yet more than twice as many buyers opted for a Capri.
As the 1970s progressed, currency fluctuations ultimately destroyed the Capri’s viability as an import. Meanwhile, GM’s F-body experienced a boomlet in popularity, particularly between the 1973 and 1979 oil crises. In 1977 Firebird output reached almost 156,000 units — a few thousand more than the Mustang II, which in 1974 had been downsized onto the subcompact Pinto platform.
So yes, the Firebird — like the Camaro — went on to have some very good years. Nevertheless, over the last half century the Mustang tended to sell better when it was smaller and lighter than the F-body.
With the 1970 redesign, GM doubled down on bigger and heavier pony cars — and never looked back. Compare the final Firebird shown below with the first- and second-generation models pictured earlier in this post. Here we have the automotive equivalent of Elvis Presley’s decline. It’s too bad GM did not put the Firebird on a diet before the downward slide became embarrassing.
SOURCES:
Auto editors of Consumer Guide; 2006. Encyclopedia of American Cars. Publications International, Lincolnwood, Ill.- Classic Car Database; 2018. “Search for specifications.”
- Flammang, James M.; 1992. Standard Catalog of Imported Cars, 1946-1990.First Ed. Krause Publications, Iola, WI.
- Gunnell, John; 2002. Standard Catalog of American Cars, 1946-1975. Revised 4th Ed. Krause Publications, Iola, WI.
- Mueller, Mike; 2010. The Complete Book of Mustang: Every Model Since 1964 1/2.Motorbooks, Minneapolis, MN.
- Old Car Advertisements; 2018. Mercury Capri (1970).
- Old Car Brochures; 2018. Ford Maverick (1970); Plymouth Duster (1970); Pontiac Firebird (1968, 1970).
- Wikipedia; 2018. “Ford Mustang” and “Pontiac Firebird.”
Well that surprised me, I guess those Mustangs weren’t as bloated as I thought. Interesting piece.
Thta’s because they were still largely using major portions of the original Mustang’s inner body/floor structure. The added a fair amount of length and width, but there’s still plenty of 1965 Mustang in these.
Meaning the extra size was pretty much a waste, which is why I’ve always rather disliked the Mach 1.
When you look under the hood of one all there is is a foot of air between the radiator support and grille, there isnt that much weight in extra sheet metal to accommodate that or the extra tumblehome on the sides. Sound deadening, chassis reenforcement efforts(65s may be light but they have the structural integrety of aluminum foil) beefier suspensions and available engines likely played larger roles in upping the weight for the Mustang between 67 and 71 than the external dimensions did.
Wow, I never would have guessed that the “Clydsdale Mustang” was so close in specs (and often smaller) than the 71 Firebird. Although that should not be a surprise, as GM was never one to build a lightweight car in those years. But that it was a bare half inch wider and smaller in all the other dimensions you cite (except an extra inch of wheelbase on a car of shorter length) is completely new to me.
I would argue that the manufacturers’ desire to cater to performance enthusiasts drove the increases in size. You can’t stuff big cubic inches in a small, lightweight platform like the 65 Mustang.
The ’71 Mustangs (and Cougars) were lengthened and widened specifically to fit the 429 engine (that was shoehorned into a few hand-built 69-70 Mustangs as the Boss 429). But when the cars came out in the fall of 1970, the market was in decline due to a recession and the insurance industry’s attack on muscle cars in the form of exorbitant surcharges in rates for such vehicles. And upcoming emission mandates and lowered compression ratios of engines would greatly reduce power. The 429 would only be offered on these cars in 1971 and dropped for 72-73 when a 351 Cleveland was the top engine. The ’71 Mustangs had the blessing of former Ford president Bunkie Knudsen, who was fired by Henry Ford II in September, 1969. Lee Iacocca, who shepherded the original Mustang, was named president in December, 1970 and immediately saw the writing on the wall for the porky ’71 Mustangs and ordered a downsizing of the 1974 model, first having designers build on the Maverick platform and then the Pinto, ultimately choosing the latter due to several advanced engineering features such as standard front disc brakes and rack-and-pinion steering, and the success of the similar-sized Capri at Lincoln-Mercury dealers. The result was the ’74 Mustang II that came out in the fall of 1973 as the Arabs turned off the oil with the infamous embargo, creating an instant market for smaller cars such as Mustang II, Pinto and the imports.
This analysis is spot-on. To really appreciate the length of these Gen. II F-Body cars, look at the hood on a 1979-’81 Firebird. Something about the front-end redesign of those Firebirds really accentuated the unusually long front end of those cars. They almost look cartoon-like today.
Despite the 2nd gen F Body’s bloat, especially the Firebird, I think GM worked hard to compensate with good suspension, brakes, steering, etc … unlike the Mustang. Though of course the Fox Mustang then leap-frogged past, though it took the Fox a few years to get there in execution.
If the chassis and suspension of the F-body could be considered ‘good’, it was only in the context that the suspension of any GM car was good. GM went the route of using essentially the same, full-size suspension on all of their vehicles; they simply just cut it down to fit, then bolted it up to the front of the unibody.
I think this is a big reason the smaller GM cars ended up being the heaviest in their respective classes. Of course, there was the benefit of the bigger engines actually fitting in the engine bays, too. Stuffing a big-block into a sixties’ Mustang or Barracuda was tough with lots of compromises. With a GM ponycar (of any vintage), it was all plug-and-play.
Ford might have scored big with the Mustang, but GM did an admirable job of following up with the F-body.
“The wheelbase ahead of the front wheels is cut by four inches”
I’m not understanding how that works. It would seem that the wheelbase could be diminished either behind the front wheels, or ahead of the rear wheels – it’s difficult to tell from the revised photo as other features have been modified, such as the door cutline to the rear wheel opening, which actually appears larger in the after photo.
I think that he’s actually referring to the front overhang. That’s nothing but sheetmetal. Have you ever seen the radiator shroud of a first gen Monte Carlo? Looks a garbage can got stuck in there. That first picture of the Firebird Formula? Gorgeous! Some guys liked Twiggy. Some liked Sophia Loren.
Everyone has their own opinion about the design of cars. However, to this (retired) designers’ jaded eyes, BOTH the 70 1/2 Camaro and Firebird were timeless design beauties. Personally I’ve always preferred the slightly more lithe looking Camaro, but I wouldn’t push a Firebird out of my garage either!
Given the commonality between both F cars, GM Design did a superb job of creating individual identities on the second gen. cars……..IMhO. 🙂 DFO
As an aside, I always thought the OHC 6 was a good engine that, with a bit more development, could have been the great engine that helped GM get through the Malaise Era. But alas, it’s life was cut short.
Cut short by Americans (most of them) that were of the mind that if you got a Six, you were a cheapskate. Never mind if the Six was a better or more powerful engine, if you got the Six, people just assumed you couldn’t afford the Eight.
I can see an alternate reality where the Sprint Six became the best engine of the Malaise Period, perhaps with a turbocharged engine in a Pontiac variant of the Buick GNX. It was certainly a better engine than the 3.8 liter, especially the early odd-fire version.
But even if it had lived on, the Sprint Six would have died at the end of the RWD era, whereas the 3800 could (and would) be turned sideways for FWD applications.
Nice article. I’m going to play devils advocate for a minute, but don’t think I didn’t appreciate the posting or the work behind it.
1. The ’71-’73 Mustang was from a period when Ford went completely stoopid. It wasn’t just the Mustang- the Pickups and Broncos were the only thing that weren’t off the styling hook.
2. Mopar entered the ponycar fray late, with a decent looking car with horrible build quality. It didn’t handle all that well eiher, and a (much less expensive) Duster could give one fits on the dragstrip.
3. Much to everyone’s surprise, the Trans Am turned out to be the last man standing in the musclecar period. Why was that? It handled and stopped as well as it went, andit was the best balanced ponycar out there.
The Capri (for a short time) and the Celica remained competitive for awhile in this market. Go down and try to buy a new one right now. But guess what- the Camaro, Challenger, and Mustang await your inspection.
Technically, Mopar entered the ponycar market early by releasing the Barracuda three weeks before Ford introduced the Mustang… I guess ponycar had a better ring to it than fishycar.
Supposedly Bunkie Knudsen, who went from GM to Ford, and also added the Pontiac Beak to the 1970 T-Bird, authorized a “mid size Mustang” for 1971. “To compete with mid size coupes” such as LeMans, Chevelle, and Charger. Saw this in some write ups of the ’71.
yes, the doors were long. and heavy. more than once I had to help my next door neighbor re-shim the door hinges to compensate for sag.
I’ve never particularly liked huge cars, and I’ve always gravitated toward smaller, more powerful automobiles. Such vehicles satisfy my needs of a car that is easy to park and nimble on the mountain roads so common in my area.
Thus I’ve never understood the hype for big block pony cars. Everybody and his dog talks about how fantastic they were, But all of the big block pony cars I’ve ever driven were absolutely awful. The chassis of said cars could not handle the weight and power of the large engines, and the whole exercise was kind of a waste of time as a good 289 Mustang is in fact a much nicer driving car than a 390 Mach 1.
It is interesting to see how the sales number for this out in reality. Although it could not be completely ascribed to the size of these cars, previous generation of smaller cars were certainly more popular. partially it is because the buyers moved to bigger and larger family cars as they matured and also due to insurance regulations regarding pony cars.
Most of the cars and trucks I see on the road today are gigantic things and I really don’t want anything to do with them. For me, anyway, bigger is not always better.
GM had absolutely brilliant marketing on the big-block ponycars. They really hit the sweet-spot during the musclecar heyday between 1967-69.
So, Ford and Chrysler wanted to get in on that big-block, big-profit action, as well. Unfortunately for them, that early three year period was pretty much it for the big-block ponycar. By the time they got their big-engine cars into production, it was all over. It didn’t help that by any other performance metric other than a straight-line, big-block ponycars were pretty miserable. They weren’t much fun in day-to-day driving.
It’s worth noting that while the big-engined Firebird Trans Am enjoyed enduring success throughout the seventies, the big-block second generation Camaro was very short-lived, only lasting through 1971 with very low sales (and it was only with the 396, too).
I find it interesting that you perceive a meaningful difference between a small–block and big-block mustang of the classic generation. There must be one, but as someone under 30 who grew up with today’s cars, any vintage American car I’ve been able to drive, I felt uncomfortable operating at more than mild cruise speeds. All the controls are just so vague and… no matter how slow I drove the cars always felt somehow squirrely, like they’d wander right off the road if I let my guard down for even a second.
To be fair, even my buddy’s well-kept Celica feels iffy to me on the highway, and that’s an early 90s car…
It’s too bad GM did not put the Firebird on a diet before the downward slide became embarrassing.
Did it?. The Capri flamed out after a few years and pretty much every small “European” like sporty car is loooooong extinct, save for the Miata and languishing Toyota 86 today, while ponycars hung around and remained modest sellers despite being even heavier than these early 70s examples. Hell the Challenger is the heaviest and largest of the bunch and its sales have been shockingly stable for 10 years.
The downward slide of the Firebird and Camaro had zero to do with bloat IMO, it happened under the watch of the LIGHTER 3rd and 4th gens with the cheapening out on materials, awful quality overwrought styling, poor packaging(NOT space efficiency) and to some extent the association with GM itself. Bloat wasnt responsible for any of this, and whatever bloat there was didn’t hurt them in performance measures, as F bodies always compared favorably in acceleration and handling to the competition
The Capri was killed by exchange rates, not anything intrinsic to the car itself; the fact it held on as late as 1977 despite this and internal competition from the Mustang II speaks well for it. The Celica was popular through 25 years and several design cycles.
Another factor is the popularity starting in the ’80s of hotted-up versions of regular sedans, as well as the increasing performance of the not-hotted-up ones.
Not disputing that, especially the latter point. Sport sedans essentially rendered the segment obsolete, as the underpinnings from manufacturers of both were usually identical and the stigma of the boring sedan had essentially vanished overnight.
The ponycar of the 80s and beyond split from its mainstream sedan based roots as the Fairmont/LTD were replaced with Tempos and Tauruses and the 3rd gen F body got its own chassis. Inadvertently these became “bloated” themselves despite their late 70s downsized origins, as cars like the Celica remained small and switched to FWD, and these remained RWD with heavy V8s. Ultimately while platform shared ponycars made a lot of business sense, it could be argued that the bloat is what kept Mustangs alive and revived the Camaro and Challenger as smaller more lithe “ponycar lites” unceremoniously died off. It’s simply a more unique product than if it became the Probe, which was more inline with the Celica.
Also, the PLC likely played the same role in the 70s to erode Ponycar sales as the sport sedan did the next two decades. These were essentially the same formula as a Mustang or Camaro, just based on intermediate sedans rather than compacts. Bloat certainly didn’t do those in.
The ponycar bloat still continues today:
2018 Camaro
Curb weight: 4,113
Dimensions: 188″ L x 75″ W x 53″ H
2018 Mustang GT
Weight: 3,705
Dimensions: 188″ L x 75″ W x 54″ H
1967 Camaro
Curb weight: 2,920
Dimensions: 184.7 in L x 72.5 in W x 51.4 in H
1965 Mustang
Curb weight: 2,800 (weight with the six was 2,445)
Dimensions: 181.6″ L x 68.2″ W x 51.2″ H
Whoa, where’d you get that ’18 Camaro curb weight from? Even the convertible doesn’t weigh that much (3956 lbs). The coupe weighs 3700-3800 pounds.
From Chevrolet 🙂
Curb Weight
(lb. / kg):
3883 / 1761 (coupe w/manual)
3944 / 1789 (coupe w/automatic)
4113 / 1866 (conv. w/manual)
4148 / 1882 (conv. w/automatic)
3820 / 1732 (ZL1 1LE – est.)
https://media.chevrolet.com/media/us/en/chevrolet/vehicles/camaro-zl1/2018.tab1.html
The current crop of muscle cars are as bloated and expensive. The only folks interested in them are 50+ gray haired old men with fat pensions or inflated 401k accounts.
Would be nice if the auto companies could come up with something small, cheap, fun, and grab the attention of millennials like the Capri or early Fiat 124 spiders did in the late 60’s and early 70’s. Don’t worry about the lawyers or penny pinchers, focus on the fun factor.
I was sad when the Nissan iDX concept didn’t reach production, or either of the Chevy Code concepts. One was supposed to be a compact RWD model which I understood probably couldn’t have been supported by any of GM’s platforms but the other was a FWD Delta derivative. Would’ve made a great Cruze coupe.
That being said, how well are small coupes selling anyway?
The early 70s decline could also be tied to the overall pony car market decline, which was primarily attributed to rising insurance costs for pony cars, and then the first gas crisis. In general, Americans are partial to larger cars as long as gas is perceived to be affordable, I think.
The fuel crisis did not come until 1973, well after smog controls sucked the guts out of all of the V8s coming out of Detroit. Ponycar sales really started declining even before the major detuning began in 1971-72. Insurance had a lot to do with it, but it was style as much as anything else. The oldest baby boomers were 20 in 1966 when performance was king. They were 25 in 1971 and either 1) in Viet Nam 2) protesting Viet Nam or 3) married and trying to hold down a job and raise a family. Practical, inexpensive cars were where the action was in 1970-75.
While I’m sure a sizeable of former or would-be ponycar buyers flocked to practical inexpensive cars, the Personal Luxury Coupes like the 69+ Grand Prix, Monte Carlo and their imitators became massive hits in parallel to the ponycar’s declining sales as well. In concept they are the same with the long hood short deck proportions, they just have more room(relatively speaking) that would appeal to buyers who needed it but wanted the stylish looks and proportions of the ponycars.
Interesting exercise. Your reworking of the blue Firebird is an excellent example of the compounding effect of multiple subtle changes. I’m not sure it’s an improvement, however – that long hood goes a long way to making that F one of the best shape/platforms ever from the US. A period that was admittedly peak bloat, but to this foreigner’s eyes was also when US styling reached it peak (contentious, yes).
Surprised the Capri sold as well as it did once people figured out it was a tinny rustbucket. I remember as a kid these had big holes in the body after 3 years. I liked the big mustang, didn’t like the Camaro or baby mustang. I don’t think the firebird was to big. It looked nice especially 77-78 .trans am However an early 70s big mustangbeat it for power, economy, comfort and simplicity.
Firebirds were really overbuilt since there was no small block engine. The 350 was the same weight and outer dimensions as the 455.
The six would have been better received had it not proven so troublesome, detonating right off the showroom floor leading to blown head gasket. Needed a LOT more development.
These responded well to aluminum intake and heads, the cast iron air gap intake manifold alone needed an engine hoist to lift it!
Does that mean the 301 block has the same dimensions and weight as a 455???
Fascinating to compare the 1970 Firebird with the less-overhang Photoshop, which seems kinda ‘Vette-like to me.
I mostly paid attention to Mustangs back then, but remember how quickly it bulked up, if only to get the bigger V8’s in there.
Today’s tale brought to mind the 1967 Cougar (we can argue whether it’s a “pony car” or not)—111″ wheelbase, and 3119 pounds, smallest engine being the 289 V8. Length is 190.3 inches, so less overhang, %-wise, than either the ’67 or ’71 Firebird.
Very interesting and thoughtful article. I had a 72 Firebird (not a Trans Am) and still consider it the best looking car I ever had. GM (and Bill Mitchell) hit a home run with these – especially the pure 70 1/2 to 73 models. They have a sinewy “in motion” shape, similar to the 64 Stingray.
Yes, they may have been a tad heavy but they handled better than any other equivalent US built model.
They’ve acquired the “mullet driver” stereotype over the years, but a stock 71 or 72 Trans Am (or Z-28) is a true thing of beauty.
Nice job on the downsized photoshopped Firebird. The proportions look better to my eyes. The 2nd gen was too big. I drove one once and reversing movements were near impossible to judge properly due to the sheer size of the thing at the back coupled with the lack of visibility.
3rd gen is the best Firebird for me. The proportions when viewed from the side are a little odd due to the overhangs but the overall size is much more manageable.
I never got the whole muscle car thing. Muscle cars just kept adding bigger engines and more weight to chassis that were marginal to begin with. Maybe it’s one of those you had to be there cultural things the Beatles’ Yellow Submarine. I like the Beatles’ and I like art so Yellow Submarine should be a slam dunk but somehow it just leaves me scratching my head. How do the horses run underwater? How does the Submarine travel through time? Why are Blue Meanies afraid of trombones? I like cars and I like performance so muscle cars should be a slam dunk. Yet when I see a big block Mustang I just scratch my head. How does it handle with all that weight in the front? How do you control wheelhop? Why do I want a car like this?
Because it,s big,brutish and American!!
In a word, marketing. I once read that the musclecar era was a marketing-man’s wet dream. That pretty much sums it up. All one has to do is look at any of the print advertisements from the sixties, beginning with the original GTO, all the way up to the day the last big-block Road Runner rolled off the assembly line in 1974.
But even the alluring and provocative advertisements couldn’t overcome cost. After 1970, it just became way too expensive to own and drive a gas-guzzling, nose-heavy, inefficient musclecar for daily transportation.
There’s big block muscle cars and small block muscle cars. By my observation the writing was probably on the wall for big blocks even without emissions regulations, big insurance premiums or the energy crisis on the horizon by 1970. More impressive engineering efforts were being made in improving lighter more efficient small block engines for high performance in the late 60s, with results like Ford’s 351 Cleveland, Chrysler’s 340, and of course Chevy’s always venerable small block, which all gave up very little to big blocks in acceleration. The CJ428 May have put the Mustang on the high performance radar, but the 351C kept it there until the Mustang II came out.
As for the want, because they were fun and whimsical, they were from a very strong period of car design from Detroit, which very often looked more complete and resolved with the Muscle car package trim, scooped/bulged hoods than in standard form, and motorsport at the time was more glamorous and not near as far removed from mass production cars as today.
In a word, burnouts!
The high compression 70 1/2 could cook both back tires into 2nd gear easy. Torque is a wonderful thing on the streets..
’72 F body production numbers were quite low due in large part to the UAW strike of GM. That one was particularly rough, lasted quite awhile and impacted Firebird and Camaro numbers rather severely.
But the size is much of these cars appeal isn’t it? I can’t imagine the serious enthusiast would have gone for a car with such a primitive drivetrain.
I feel like a Firebird is more of a stop-light cruiser and drive-in head-turner, and for that you need the biggest car with the longest hood and the loudest exhaust. I once saw a Z28 of this gen with a custom widebody, sickest car I’ve ever seen.