WHY? are 71-73 stangs so big?

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Well does not really explain why they got bigger, just that Bunkie Knudsen wanted it so, as he though Americans wanted bigger cars. Mustangs were getting bigger on every redesign. The 67-68 cars were bigger than the 64-66, and the 69-70 were bigger than the 67-68, so it comes to reason that the 71-73 would be bigger than the 69-70, and the biggest of them all. I have heard of some reasoning behind this, besides the obvious one, which is they needed to be at least partially bigger in 71-73 to handle the 385 series big blocks. The other reasoning was that Ford was loosing market share to the competition. They though that the young people that bought Mustangs when they came out in 1964 now had families and kids and needed a bigger more comfortable car to carry them around. They knew that the young kids that originally bought the Mustangs were moving onto bigger cars because of the growing size of their family, and they thought that they could bring them back into the Mustang fold if only they could more comfortably fit their current family size. I guess that this was appreciably disproven by the fact that when they went back to the "small Mustang" in 1974, which was close in size to the 1964 cars, they sold almost 400,000 of them, which is almost what they sold of the 1971-1973 cars combined. Now, the fuel crunch made a big impact on the sales of the small, sporty, and much more fuel efficient 74's, so it is hard to say what would have happened had there not been a fuel crunch.
 
I was out the other day measuring cars to size up a new garage. The 1973 mustang is the longest one of all, thanks to the longer front bumper over 71/72. My 69 tbird is longer than the 73 mustang by 4-6 inches.

There's an old man who runs a store here in town. Every time i pull up in the tbird, he tells me his story about how he bought a 68 mustang new off the showroom floor. He had a buddy who always had to 1-up everybody else. The buddy went out and bought a 69 tbird off the showroom floor. It was bigger and nicer and had way more options than they even offered in the mustangs. Back then there definitely was a connection between bigger car = nicer car.
 
Big cars were a status symbol. The bigger the car, the more successful you appeared to be. For 1971, Ford produced almost 150k Mustangs, but over 400k of the Torino, and over 900k of the full size models.
 
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Back in the 70s and 80s I really did not the 71-73 Mustangs at all, as I thought they were bloated looking. My favorite year Mustang was 1969, followed immediately by 1970. That preference continues to this day. Back then I had two 69 Mustangs, a Candyapple Red coupe and later a 69 Mach 1. I liked them bot, but the Mach 1 was much faster, especially after I built its 351W into one heck of a street/strip engine. The first attached photo is circa late 1972 showing my Champagne Gold Mach 1 in the foreground. I was 19 at the time, just before going into the Army.

Then "life happened," and I had a wife and two kids. My Mustang days took a multi-decade hiatus, util 2017 when we acquired a 1969 Shelby GT500, The next year we picked up a 1973 Mach 1, the year after we also purchased a 1973 Mustang Convertible True Survivor with under 20,000 original miles on it after being barn stored for over 40 years. Finally, in Summer, 2019 we order our 2020 Shelby GT500. Despite how awesome the 2020 GT500 is, the 1969 Shelby remains my favorite car of all time - nostalgia wins the day I suppose.

Anyway, back to 71-73 Mustang. Before we purchased the 73 Mach 1 we used to drive by it every day for about 17 years, and I always admired how it looked, despite being a "bloated design." It grew on me. And once we owed it and I began to work on it, I saw close it was to the 1969 & 1970 Mustangs in so many ways. it performed well, and handled much better than I had anticipated. We ended up doing a deep re$toration on it, and I became an even bigger fan - especially after we did some upgrades to it. The latest upgrades included installing an exhaust cross-over pipe t help take the harsh edge off its exhaust tone, and transplanting an AOD in place of its C-4 auto tranny. The AOD was an excellent move as it not only dropped the engine RPM at 60 MPH to just under 3,000 RPM to just under 2,000 RPM (3.5:1 TractionLok rear axle gears), it also pushed its top end speed up a few notches, which we can take advantage of with the OverDrive gearing as the engine (being built) has plenty of torque and horsepower to deal with the air resistance at high speeds.

In any event, I am now a raving fan of the 71-73 Mustangs, and am pleased to see there is a general swing in interest to those model years. It may have been driven by the lower prices the 71-73 Mustangs generally commanded but no matter the reason it is nice to see they are being appreciated by so many folks. Further, as observed by others in
this thread, when I put our 2020 Shelby next to out older pony cars, the 2020 looks (and is) larger. And it is also heavier.

 

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Hi Rod,

Had to jump in on this one and have a rant. Thanks for putting this one up for attention. It's been kicked around the Forum over the years from time to time, and always gets a reaction.

Speaking for my self, i have had a gut full of negative critisism that has come from many different quarters of society over the years (especially from the 1965 to 1970 brigade), regarding the oversized, bloated, large dimension 1971 1973 Mustangs. Enough is enough!

I have gone to the trouble of compiling a body size comparison chat below to demonstrate the rise and fall and rise again of the Mustang models from 1964 1/2 to the present day. This chart tells an accurate story of the difference in the sizing as the years rolled on. The reality is that, yes, the 1964 1/2 Mustang started out a fairly compact car, but grew in size up to the year 1970. FACT! ( you rarely hear the 65 to 70 brigade talk about that do you) And yes, from '71 to '73 came the biggest body sizes so far, but not what you would call dramatically large from 1970. OK, 1974 saw the bodies shrink back to a more compact size, but the chart shows a steady increase ending in 1993 close to the same size as around the 1965/67 Mustangs. This trend remained until the fifth and sixth generation Mustangs started showing body sizes very close to our '71 to '73 Models. (see my chart)

So the bottom line is yes, they started out small,then got bigger ('71 to '73), then got smaller, then bigger up to the present day, where they are very close to the 1971,2,3s. So what's the big deal, as to getting hung up on the sizes of Mustangs throughout the six generations. You don't hear of anyone crapping on as to how big and bloated and oversized the present day Mustangs are do you! Mmmmmmmmmmmmmmmmmm. :unsure:

So to all the 1971 to 1973 size critiques, GET OVER IT, and realize the fact that all car manufactures change their body sizes as the years and models roll on whether you like it or approve of it or not.

Greg.
 

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Some people hate on the 71-73's their size, I say BOO! I had a 2015 SS Camaro and it was just as big as my '71 Mach and much heavier. I take the Mach to car shows and it ALWAYS draws a lot of attention and interest. People like it, A LOT. We've got no worries about our cars.
 
Correct me if I'm wrong, but wasn't the reason why the 71-73's got 2" wider, was to fit the 429 in there? (2" wider than the 69-70) Other than that, they aren't that much bigger.
BUT, size matters........... she said!!
That is what I have always heard, they had to get wider to get the 385 series big block in there. These cars were just 2 inches longer and 2 inches wider than the 69/70 cars, and they were actually lower, it was not a big difference. If you put them side by side, it is very hard to tell that the 71 is actually bigger. The issue is that the body proportions of the 71-73 make them look bigger than they actually are, I can't really explain why, but they just look a lot bigger than what they really are.
 
Some people hate on the 71-73's their size, I say BOO! I had a 2015 SS Camaro and it was just as big as my '71 Mach and much heavier. I take the Mach to car shows and it ALWAYS draws a lot of attention and interest. People like it, A LOT. We've got no worries about our cars.
That is the other elephant in the room, weight. the 71-73 cars are heavier than the earlier Mustangs, but I am not sure anyone really knows by how much. I have seen 150-200 lbs heavier than a 69-70, but I doubt that it would be that much. Those 2 inches of width and length, should not make that much difference. Now, compared to modern cars they are quite light, seems that people who have weighed these cars claim that with a 351 Cleveland they weigh about 3500/3600 pounds. A 2020 GT500 weighs 4,200 pounds, a 2020 Challenger Hellcat weighs 4,400 pounds, and a 2020 Corvette ends up weighing about the same as a 71 Mustang with a 351 Cleveland, which is almost incredible, as it only has 2 seats and a ton of fiberglass and aluminum components....
 
I don't understand why our car's size is such a big deal to people. If you don't like it, leave it. Why downplay something others like? If I see a car I don't like I'm not gonna vent it coz I want their owners to feel great about their cars just like I feel about mine. This discussion really is all about..... nothing.
 
If interested, attached photo is my actual scale weight with full tank, tool kit and misc. trunk stuff(20 lbs), 1972 Mach, 351c, manual tranny:
FYI: my 72 is 105 lbs LIGHTER then my friends 1970 428 Mach with c6, weighed the same day. (it was a great day for me with friend betting lunch and beer 🤑)
 

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That is what I have always heard, they had to get wider to get the 385 series big block in there. These cars were just 2 inches longer and 2 inches wider than the 69/70 cars, and they were actually lower, it was not a big difference. If you put them side by side, it is very hard to tell that the 71 is actually bigger. The issue is that the body proportions of the 71-73 make them look bigger than they actually are, I can't really explain why, but they just look a lot bigger than what they really are.
Indeed, but this subject could get 'off track' in a hurry if we start comparing "size"!!
As someone with some design training, it comes down to perception created by lines. Certain lines can create the illusion of bulkiness, while others create the illusion of sleekness. Get the idea? On our cars, I think the illusion is caused by the styling along the fenders, through the doors, blending out in the quarter panel. Take that away and these cars would look no bigger then the 70 body. Also, the 71-73 cars are a bit lower and also give the illusion of being bigger.
 
If interested, attached photo is my actual scale weight with full tank, tool kit and misc. trunk stuff(20 lbs), 1972 Mach, 351c, manual tranny:
FYI: my 72 is 105 lbs LIGHTER then my friends 1970 428 Mach with c6, weighed the same day. (it was a great day for me with friend betting lunch and beer 🤑)
Good info, thanks for posting. Shortly after dropping in the 429/C6, I weighed mine (72 Mach). I was setting it up for street racing, so I had removed the external AC hardware and power steering. For some reason I weighed it while the hood was removed and I don't recall how much gas was in the tank. My memory is playing tricks on me but I think it was 3780 w/o the hood (or was it 3870 haha).
 
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