The iconic 1964 Pontiac GTO didn’t emerge from a vacuum. Its roots can be traced back to the early 1960s and John Z. DeLorean’s vision for an American Grand Tourer, which materialized in the form of the 1961-1963 Pontiac Tempest compact car. The 1963 Pontiac Tempest, in particular, stands out as a significant step in this evolution, laying the groundwork for the performance revolution that Pontiac would soon unleash.
The initial 1961 Tempest already hinted at Pontiac’s performance aspirations, featuring half of the future GTO’s formidable 389 V8, including an optional high-performance four-barrel carburetor version. Furthermore, it incorporated a rear transaxle with independent rear suspension, a feature championed by DeLorean, although the borrowed Corvair swing axles proved less than ideal.
For the 1963 model year, Pontiac refined the Tempest formula. The rarely chosen Buick 215 aluminum V8 option was dropped in favor of a more potent, reduced-bore variant of the 389 V8. Initially presented with a modest two-barrel carburetor, this engine was advertised as a 326 cubic inch unit, producing 260 horsepower. However, the actual displacement was closer to 336 cubic inches, a detail that remains somewhat of an enigma. As the model year progressed, and with the GTO’s arrival on the horizon, a more powerful 280 horsepower four-barrel HO version of the 326 engine became available, signaling Pontiac’s growing performance focus.
This review focuses on a 1963 Pontiac Tempest equipped with the 260 horsepower engine and a two-speed automatic transmission. While not yet the full-fledged muscle car that the GTO would become, this Tempest was undeniably showing its performance potential.
The advertised “326” engine, while technically closer to 337 cubic inches, is a curious case. The reason behind Pontiac’s 326 cubic inch designation is unclear. GM’s later mandate limiting intermediate car engines to 330 cubic inches didn’t arrive until 1964. For the 1964 Tempest, the bore was indeed reduced to achieve a genuine 326 cubic inch displacement. However, this rule was famously disregarded with the introduction of the 389 cubic inch GTO, adding to the intrigue surrounding Pontiac’s engine strategy.
The 1963 Pontiac Tempest LeMans, as highlighted in the original article, could be considered a scaled-down, more affordable Grand Prix. The 1963 Tempest’s redesigned, longer, and wider body panels gave it the visual presence of a true mid-size car, even though it retained much of its original internal structure, shared in part with the Corvair. Driving the 1963 Pontiac Tempest reveals that the 326 engine, even in its base 260 horsepower form, provides ample power to readily spin the rear wheels, answering any questions about whether Pontiac should have directly installed the 389 V8.
The two-speed automatic transmission in the 1963 Pontiac Tempest inherited design elements from the Powerglide, but featured improvements over the previous “Tempest-Drive” unit used in the 1961 and 1962 models. The shifts were smoother, and the torque-splitting top gear function of the earlier version was eliminated, resulting in a more refined driving experience.
However, the combination of the torque converter automatic and the 3.09 rear axle ratio proved to be overly aggressive for the narrow 6.50-15 tires. The substantial torque multiplication led to excessive wheelspin. Applying even moderate throttle mid-turn could cause the rear end to become unstable and swing out. A higher, numerically lower, axle ratio was recommended to mitigate this issue. Despite popular misconceptions, fueled by a famous movie scene, the 1963 Pontiac Tempest did not offer a limited-slip differential. The likely reason for not utilizing the ’62 Corvair’s Positraction unit was the necessity for a larger, stronger differential to handle the V8 engine’s increased power output.
The driving experience of the 1963 Pontiac Tempest, with its potent engine, was undeniably enjoyable. Its 0-60 mph time of 9.5 seconds, while not groundbreaking, was respectable for the era. A Popular Science test of a three-speed manual version recorded a quicker 8.1-second 0-60 mph time. This model was equipped with a 3.90:1 rear axle, although this ratio wasn’t listed as an option in the standard brochure.
The later-released 280 horsepower, four-barrel carburetor HO version of the 326 engine significantly boosted performance. Car Life tests indicated a 0-60 mph time of just under 7 seconds and a quarter-mile time of 17 seconds for this configuration. This level of performance placed it squarely in the territory of the upcoming 1964 GTO, albeit with a slightly slower quarter-mile.
At highway speeds, cruising at 80 mph, the 1963 Pontiac Tempest felt relaxed and unstrained. It conveyed a sense of being a larger car, although the ride quality and engine/road noise somewhat detracted from this impression, likely due to its unibody construction.
The power steering was characterized as slow, requiring approximately five turns lock-to-lock. The 9-inch drum brakes were deemed adequate but marginal, suggesting room for improvement.
While a four-speed manual transmission (borrowed from the Corvair) existed, it was not robust enough for the V8 engine. Consequently, a three-speed manual was the only manual option offered. However, with the engine’s substantial torque output in a relatively lightweight car, the absence of a fourth gear was likely not a major drawback except for competitive driving. Even the three-speed manual was considered somewhat marginal, with reports of damage occurring from enthusiastic gear changes.
The instrument panel was a fresh design for 1963 and visually appealing, featuring four large circular openings. However, the layout details were not entirely optimized. The fact that the Corvair’s interior cabin design was deemed sufficiently spacious for the Tempest underscores the Corvair’s relatively roomy interior packaging.
Limited information was provided regarding the revised rear suspension for the 1963 Pontiac Tempest. It retained swing axles but now incorporated L-shaped control arms in place of semi-trailing arms. This modification aimed to reduce toe-in variations during camber changes. The Tempest had gained a reputation for challenging rear-end handling, characterized by snap oversteer when pushed beyond its limits. The 1963 revision offered a minor improvement but didn’t fully resolve the issue. A camber-compensating spring, similar to that introduced on the 1964 Corvair, would have been a beneficial upgrade.
The original review notably omitted any detailed discussion of the 1963 Pontiac Tempest’s handling characteristics, perhaps because its handling quirks were already well-known, or the testers didn’t encounter driving conditions that would provoke the rear end’s unpredictable behavior.
Ultimately, the verdict on the 1963 Pontiac Tempest was positive, despite some reservations about its increasing size. However, this growth was merely a prelude to the 1964 Tempest and the all-new GM A-body platform. These models were destined for further expansion and, most importantly, significant performance enhancements, spearheaded by the GTO. The 1964 and subsequent GM A-bodies marked the beginning of a profound shift in GM’s history, as these mid-size cars and their successors would eventually surpass full-size cars in sales dominance. Therefore, the 1963 Pontiac Tempest was far more than just a warm-up act for the GTO; it represented the dawn of a revolution in the automotive landscape.
Further Reading on the Pontiac Tempest and Related Models:
- Curbside Classic: 1963 Pontiac Tempest LeMans – Pontiac Tries To Build A BMW Before BMW Built Theirs, And Almost Succeeds: https://www.curbsideclassic.com/curbside-classics-american/curbside-classic-1963-pontiac-tempest-lemans-pontiac-tries-to-build-a-bmw-before-bmw-built-theirs-and-almost-succeeds/
- CC BS Buster: “My Cousin Vinny” Courtroom Scene – The 1963 Tempest Actually Did Not Have A Limited Slip Differential and The ’64 Skylark Did: https://www.curbsideclassic.com/blog/cc-cinema/cc-bs-buster-my-cousin-vinny-courtroom-scene-the-defense-is-not-wrong-the-1963-tempest-did-not-have-a-limited-slip-differential-and-the-64-skylark-did/
- Automotive History: 1963 Days – Popular Science Tests the Hot Compacts: https://www.curbsideclassic.com/automotive-histories/automotive-history-1963-days-popular-science-tests-the-hot-compacts/
- Vintage Car Life Road Test: 1964 Pontiac GTO – “Honest In Performance”?: https://www.curbsideclassic.com/vintage-reviews/vintage-car-life-road-test-1964-pontiac-gto-honest-in-performance/
- Magnificent Kludge: The ‘Rope-Drive’ 1961–1963 Pontiac Tempest (Ate Up With Motor): https://ateupwithmotor.com/model-histories/compact-economy-cars/magnificent-kludge-the-rope-drive-1961-1963-pontiac-tempest/
