Among Chevy diehards, the 1963 Impala Z11 is more than just a special-order oddball - it’s one of the most lethal, purpose-built drag-strip predators General Motors ever unleashed. Born during the heat of the early-’60s Super Stock wars, the Z11 was Chevy’s hush-hush, factory-sanctioned answer to Ford’s 427 Galaxies and Mopar’s Max Wedge brutes. Only 57 were ever built, and today they stand as unicorns - mythical, snarling artifacts from the golden era of Detroit performance one-upmanship.
Below is a deep dive into why the Z11 still makes automotive enthusiasts talk in hushed, reverent tones.
Lightweight With a Mean Streak: What Made the Z11 Special
Above and several below: In the lead photo - 1963 Chevy Impala Z11 (photos courtesy of Mecum Auctions) specifications:
- Bill 'Grumpy' Jenkins Old Reliable IV
- No. 1 of 57 RPO Z11 Lightweights built
- Driven by Dave Stickler
- Delivered new to Ammon R. Smith Auto Co. on December 21, 1962 from Flint, Michigan Assembly Plant
- Original 427/430 HP V-8 engine
- Two-piece intake manifold
- Hurst T-shifter
- Aluminum inner fenders, bumpers, brackets, sheet metal, fan shroud RC bell housing
- White exterior
- Black interior
- Vented metallic brakes
- Positraction rear end
- Tachometer
- Cowl induction
- Sound deadener/insulation/windshield wiper delete
- Stahl Engineering headers
- White underbody
- Jenkins Competition original modifications including generator in place of alternator for 5 additional HP
- Jenkins Competition line custom traction bar, line lock and vacuum switch
- Jenkins Competition 3-speed with separate lever for reverse
- Restoration by Randy DeLisio of Lyons, New York
- Original Window Sticker
- Signed air cleaner
- Complete ownership history from Ammon R. Smith, Lou Czern, Bill Jenkins, Floyd Garrett, Edward Burden and Don Fezell
- Extensive receipts and paperwork
To the casual eye, a Z11 looks like a clean ’63 Impala Sport Coupe with a subtle “street sleeper” vibe. But beneath that conservative sheet metal lurks an arsenal of factory-engineered trickery.
1. Lightweight Bodywork
The Z11 program used a mix of aluminum and ultra-thin steel pieces to put the Impala on a crash diet. Components included:
- Aluminum hood
- Aluminum front fenders
- Aluminum front and rear bumpers
- Lightweight brackets, braces, and supports
- Thin-gauge inner panels and radiator support
Chevy shaved roughly 300 pounds off the typical big-body Impala - crucial for getting a two-ton full-size car out of the hole hard enough to win in NHRA Super Stock.
2. High-Riser 427 W-Engine (The Heart of the Beast)
At the core of the Z11 was a seriously massaged version of Chevy’s 409. Engineers stretched displacement to 427 cubic inches (technically 425.9) using a longer 3.65-inch stroke crank and other internal upgrades.
But the real magic came from its high-rise intake system - essentially a tall aluminum manifold feeding dual Carter AFB four-barrels. Chevy underrated the package at 430 hp, but dyno figures whispered by racers put reality closer to 500+ hp straight from the crate.
3. Built for One Mission: Domination at the Strip
A Z11 came with almost no creature comforts - no radio, no heater, no dead weight. It was all business:
- Heavy-duty Borg-Warner 4-speed
- Bulletproof 4.11 or 4.56 Posi rear end
- Reinforced suspension and driveline components
- Optional metallic brakes for fade-free stopping
Chevy didn’t even include standard windshield wipers on some builds. If it didn’t help the quarter-mile time, it didn’t make the cut.
Video: Chevy's 427 Monster that Ford was Scared to Race -The 1963 Chevy Impala Z11
Born Into a Drag Racing Arms Race
By 1963, drag racing was no longer a weekend hobby - it was a battlefield where brands fought for showroom glory. The Z11 was Chevy’s silver bullet, aimed squarely at Ford’s new 427-powered Galaxies and Dodge/Plymouth’s fire-breathing Max Wedge cars.
Iconic racers who campaigned Z11s:
- Dave Strickler with the famous Old Reliable
- Ronnie Sox before Sox & Martin fame
- Hayden Proffitt, a west coast terror
- Butch Leal (“The California Flash”)
These cars weren’t show queens - they were weapons, and they collected W’s like trading cards.
Video: A Two-Ton Brawler That Could Run with the Best
Despite its size, the Z11 shocked both fans and competitors with its drag strip ferocity. Period-correct times:
- Low 11s with skilled drivers and tuning
- Mid 12s right off the trailer
For a full-size car on bias-ply tires in 1963, this was ferocious.
Chevy got out of the factory racing game near the end of ’63 due to GM’s corporate ban, which pushed the Z11 into immediate legend status - wildly fast, short-lived, and impossible to replace.
Production Numbers & Rarity
Only 57 units were built, all through Chevy’s Central Office Production Order (COPO) system, long before COPO became synonymous with Camaros. Many Z11s were raced into oblivion, their parts cannibalized for other competition builds. Surviving examples today are:
- Ultra-rare
- Historically significant
- Seven-figure collectibles when they appear at auction (which is almost never)
Owning one is like holding a piece of forbidden factory experimentation.
Why Enthusiasts Still Worship the Z11
Above: 1963 Chevrolet Impala Z11 - one of two produced with a jet black exterior (photo courtesy of Mecum Auctions)
The 1963 Impala Z11 represents the sweet spot of raw American performance - before the muscle car boom, before emissions, before insurance crackdowns. It’s a relic from a time when:
- Engineers were hot rodders first
- Drag racing wins translated directly into showroom traffic
- “Win on Sunday, sell on Monday” wasn’t a slogan, it was reality
The Z11 is revered because it wasn’t built to be pretty, polite, or plentiful. It was built to win, full stop.
And it did.
Final Thoughts
For gearheads who love the thunder of the W-engine, the stance of an early-’60s full-size Chevy, or the lore of factory drag racing warriors, the 1963 Chevrolet Impala Z11 is the holy grail. It’s a symbol of unrestrained innovation - Detroit at full throttle, consequences be damned.
If the muscle car era was a war, the Z11 was one of Chevy’s most fearsome early generals.
Classic Industries Offers a Plethora of Components for the Iconic Chevrolet Impala
Above: Great and informative article on the CI website: 1958-1964 Chevy Impala / Full Size Models & Specifications
When CI's honored customers need Chevrolet Impala parts, there are two great resources for searching and finding those must-have items. A wonderful place to begin is with the Classic Industries website on the 1958-1996 Chevrolet Impala shopping page. You can also greatly enhance the searching/shopping experience by having an Impala/Full Size Chevy Parts and Accessories Catalog mailed to your address. Simply click on the button below and fill out your mailing information.
Above: The 1963 Chevy Impala Z11 interior was built for comfort, style, and speed (but not necessarily in that order, if you catch our drift).
