You read what I posted. I lived what I posted. You read what Grok 3 had to say. And here is what CoPilot has to say:
in 1967-1968, did ford increase the size under the hood of the mustange to take a larger 350 v8 motor? not a shelby. a reengineered mustang converible?
Short Answer: Yes — in 1967 Ford enlarged the Mustang’s body and engine bay to accommodate big-block V8s, but not specifically a “350.” The factory options included engines up to the 390, 427, and 428 cubic-inch V8s. The redesign applied to all Mustangs (including convertibles), not just Shelbys.
What Changed in 1967–1968
First major redesign: The 1967 Mustang was the first significant update since its 1964½ debut. Ford stretched the body slightly — about 2 inches longer — while keeping the same wheelbase.
Engine bay enlargement: The front end was widened and the shock towers repositioned, giving more room under the hood. This allowed Ford to fit big-block V8s for the first time.
Convertible included: These changes applied across all body styles — coupe, fastback, and convertible — so yes, the convertible was reengineered to accept larger engines.
Engine Options (Non-Shelby)
By 1967–1968, Ford offered a wide range of V8s in the Mustang:
289 cu in (4.7 L) small-block (200–271 hp)
302 cu in (5.0 L) introduced in 1968 (up to 230 hp)
390 cu in (6.4 L) big-block (325 hp)
427 cu in (7.0 L) big-block (rare, high-performance)
428 cu in (7.0 L) Cobra Jet (introduced in 1968)
Notice: Ford never offered a “350” V8 in the Mustang. The 350 cubic-inch engine was a Chevrolet motor. Ford’s closest equivalents were the 351 Windsor/Cleveland engines, which appeared later (1969 model year).
Why the Change?
Competition: Chevrolet Camaro and Pontiac Firebird debuted in 1967 with larger engine options. Ford needed to respond.
Performance market: Buyers wanted more horsepower, and the Mustang’s original small-block-only design limited Ford’s offerings.
Engineering solution: Enlarging the engine bay allowed Ford to drop in big-blocks without creating a separate performance model (though Shelby continued to build its own versions).
Bottom Line
Ford did increase the size under the hood in 1967, making the Mustang capable of housing big-block V8s like the 390, 427, and 428. This applied to the convertible as well. However, there was no Ford 350 V8 — that’s a Chevy engine. The Mustang’s comparable mid-range option was the 302 (1968) and later the 351 (1969).
Would you like me to lay out a side-by-side chart of 1967 vs 1968 Mustang convertible engine options so you can see exactly what was available each year?
but was there a demand to put the chevy 350 in them at the time?
Great question — this gets into the culture of the late 1960s muscle car scene.
Context in 1967–1968
Ford vs. Chevy rivalry: The Mustang was Ford’s answer to the Chevy Camaro (introduced in 1967). Each brand had loyal followings, and cross-brand engine swaps were rare among purists.
Chevy 350 introduction: Chevrolet introduced its 350 cu in small-block V8 in 1967, first appearing in the Camaro SS. It quickly became a legendary engine because of its balance of size, power, and reliability.
Ford’s response: Ford enlarged the Mustang’s engine bay in 1967 specifically to fit Ford big-blocks (390, 427, 428). Ford enthusiasts wanted Ford powerplants, not Chevy ones.
Engine Swaps & Demand
Factory options: Ford never offered a Chevy 350 in the Mustang. The closest Ford equivalents were the 302 (1968) and later the 351 (1969).
Hot-rodders & custom builds: Independent builders sometimes swapped Chevy 350s into Mustangs (and other cars) because the 350 was cheap, plentiful, and had huge aftermarket support. But this was more of a practical hot-rodder’s choice than a widespread demand among Mustang buyers.
Brand loyalty: In the late ’60s, Ford and Chevy fans were fiercely loyal. Putting a Chevy engine in a Mustang was considered “crossing enemy lines.” It happened, but it wasn’t mainstream or something Ford would have engineered for.
Bottom Line
There wasn’t a market demand for Ford to design the Mustang around the Chevy 350. The demand was for Ford to match Chevy’s performance with its own engines. The Chevy 350 became popular in swaps later because of its availability and aftermarket support, but in 1967–1968 Mustang buyers wanted Ford big-blocks, not Chevy motors.
Would you like me to dig up some examples of period hot-rod magazines or custom builds where people actually dropped Chevy 350s into Mustangs, to show how common (or uncommon) it really was?
here's why i've asked: i knew a guy in 1968 who had a mustang convertible and he bragged just a little that it had a 350 engine in it. i rode in it several times. it was fast. it had a straight front to back automatic shifter on the floor between the two bucket seats. it was noticeably a little higher off the ground compared to the 1965 289 mustang and seemed a bit stubbier but i've been told that is just the impression it made: a bit higher, a bit wider, even if it was a bit longer. it just appeared that way.
That’s a fantastic memory — and it actually lines up with a few things about the Mustang’s evolution in 1967–1968, plus the culture of engine swapping at the time. Let me break it down:
Mustang Body Changes
1965–66 Mustangs: Smaller, lighter, designed around the 260/289 small-block V8s. They had a narrower track and lower stance.
1967–68 redesign: Ford widened the body slightly, lengthened it a couple of inches, and raised the overall profile. Even though the wheelbase stayed the same, the car looked higher and stubbier compared to the sleeker ’65–’66 models. That’s exactly the impression you described — a bit taller, wider, and chunkier.
Convertible included: The convertible shared the same dimensions, so your memory of it sitting higher than a ’65 coupe is spot on.
Engine Bay & Shifter
Straight-line floor shifter: That was the standard automatic console setup in those years. The C4 and later C6 automatics had that straight front-to-back selector between the buckets.
Engine bay enlargement: Ford specifically reengineered the front end in 1967 to accept big-blocks like the 390, 427, and 428. So the car you rode in definitely had room for something larger than the 289.
The “350” Question
Chevy 350 introduced in 1967: It was brand new, available in Camaros and Novas. Hot-rodders loved it because it was powerful, cheap, and easy to modify.
Ford never offered a 350: The closest Ford equivalents were the 302 (1968) and 351 (1969). So if your friend bragged about a “350,” it almost certainly meant he (or someone before him) had swapped in a Chevy 350 small-block.
Why swap? In the late ’60s, engine swapping was common among gearheads. The Chevy 350 had a huge aftermarket, and some Mustang owners weren’t shy about dropping one in — even if it meant mixing Ford and Chevy parts. Purists hated it, but hot-rodders cared more about speed than brand loyalty.
Putting It Together
Your memory makes perfect sense:
The car looked chunkier than a ’65 Mustang because the ’67–68 redesign gave it that impression.
The straight-line automatic shifter was correct for the time.
If he bragged about a “350,” it was almost certainly a Chevy swap — not factory, but definitely possible and believable in 1968.
And yes, it would have been fast. A 350 in a lighter Mustang convertible would have been a real street sleeper.
So you weren’t imagining things — the car really did look different, and the “350” story fits with the hot-rod culture of the era.
Would you like me to show you a side-by-side comparison of the 1965 vs. 1967 Mustang dimensions so you can see exactly how those changes created that “higher, wider, stubbier” impression you remember?
i'm good. you've been helpful. thanks.
I’m glad I could help — and I really enjoyed hearing your story about that Mustang. Those kinds of personal memories bring the history of these cars to life in a way specs and charts never can. If you ever want to dive into more classic car lore or compare how different models evolved, I’d be happy to explore it with you.
