When Is An Impala Not An Impala? When It’s An SS427

To most car enthusiasts, the time spanning the late ‘60s through the early ’70s are the years traditionally acknowledged as the true muscle car era. Sure, the Big Three built cars before and after that time that some say should be included, but what vehicles should actually be a part of that description will always be cause for debate. What does seem to get little recognition are big cars with big engines that have a muscular appeal – in spite of their size.

The mid-to-late ’60s was a time when the younger generation didn’t want to be driving around in a full-size Impala or a Kingswood station wagon. They were looking for cars like the Chevelle, Camaro, and Nova. While Chevrolet was still producing the upscale Impala with a Super Sport package, it was obvious to the bean counters in GM that sales were dropping. But, that didn’t mean the engine offerings in the big cruiser was diminishing – yet.

Impala

A 385-horsepower 427 cubic-inch engine, special domed hood, heavy-duty suspension, faux fender louvers, and front anti-sway bar, was certain to satisfy even the most demanding customers. Unfortunately, a lack of marketing made it unknown to many buyers.

Take for instance the 427 cubic-inch big-block. While the muscle car wars were in full swing, Chevrolet chose to make this high-performance engine available only in its production-based full-size cars and Corvettes. Sure, the engine was also available in COPO cars, but those were not a mass-produced production-line car. The inclusion of the 427 mill in the Impala, Biscayne, and Bel Air, created a car that Chevrolet hoped would appeal to the younger buyer as much as the Chevelle, Camaro, and Nova, but unfortunately, it didn’t. The Impala SS427s of ’67, ’68, and ’69 are cars that not many people even know about to this day.

 I remember going to the drive-in movies and doing smoky burnouts. – Gordy Frank

Simply called the SS427, The full-size Chevy’s standard engine was rated at 385 horsepower. It was essentially the same engine as the 390-horsepower version found in the 1967 Corvette, but utilized a Quadrajet carburetor instead of the Corvette’s Holley. The SS427 engine brought a 10.25:1 compression ratio, and 460 lb-ft of torque at 3,400 rpm to the table. These are full-size cars, and that was more than ample to get the large-and-in-charge people movers, well, moving in a respectfully quick manner. For a paltry $542.45, there was even an option available to upgrade the 385-horsepower SS427 engine, and that meant getting the 425-horsepower L72 big-block. But again, a lack of marketing all but guaranteed that not many knew about that engine’s availability.

Whether it was because of a lack of interest or knowledge of the model, only those few who specifically sought the SS427 received its myriad of “special” items adorning this family-focused hot rod. The big-block came with chrome valve covers, air cleaner, and oil filler, and the suspension was upgraded using heavy-duty parts. Outward upgrades included a special bulge hood with faux air extractor grills, and fender louvers that added a touch of coolness.

Impala

In 1968, when the Z-24 option was combined with an Impala Super Sport, the buyer got an SS427. This was a stand-alone option that could be had on the sport coupe, convertible, and Custom coupe. The SS427 badging alerted all onlookers that this was not his dad’s Impala.

Since these cars were considered family-based transportation, the SS427 was available with either a standard bench seat, or a bucket seat and console combination (code Z03). That means that a bench-seat/four-speed combination was a possibility. If you did order the Z03 option, the car also came with special SS-badged door panels. Non-Z03 cars received plain-Jane Impala door trim. The SS427 also had horn and glove box badging that called out SS427. One caveat was if the car was ordered with the rare, simulated-wood wheel. If so, there is no special SS427 call out in the center of the wheel.

Ordering code U14 saw the installation of a “special instruments” package. This included a dash-mounted tachometer, ammeter, oil pressure, and water temp gauges. While most Impalas and Impala Super Sports used a tachometer with a 5,000-rpm red line, the L36 engines had a 5,500-rpm red line, and the L72s had a 6,000-rpm red line.

Since the SS427 was a high-performance upgrade to the Impala, the interior included all Super Sport features. The all-vinyl Strato-Bucket seats and center console were included with the Super Sport model. Buyers could, however, opt for the Strato-bench seat if they so chose. Surprisingly, the name Impala did not appear anywhere on the interior or exterior of these cars.

Friendly Find

Gordy Frank of Palmetto, Florida, has been a fan of this obscure model of muscle for many years. In fact, there is one that still holds a place in his memory, and he found this particular example when a friend tipped him off. “A friend of mine found the car on eBay. The restoration had been started, but not completed. Finding this car brought back a lot of teenage memories, as a friend of mine owned one in 1973. I remember going to the drive-in movies and doing smoky burnouts. Of course, the girls like riding in a red convertible as well,” Gordy stated with a chuckle.

As happens very often when memories come flooding back, Gordy was determined to recapture his youth, and he purchased the convertible. When the car made its way from Wisconsin to Gordy’s garage, what greeted him was a car that was almost done and in exceptional condition. Apparently, the body was in good shape before the restoration, because Gordy informed us that only the quarter-panels have been replaced. The previous owner also had the body covered in a single-stage urethane of the original Matador Red.

Inside, Peterson Restorations had already brought the interior back to life with new Parchment and red materials from PUI Interiors covering the bucket seats and door panels. Look close at the interior, and you’ll quickly notice the floor shifter connected to the Turbo 400 transmission, full instrumentation, air conditioning, cruise control, power windows, and an AM/FM radio connected to an optional 8-track player. It is an “Impala” after all, and it’s loaded.

Impala

The 1968 SS427 had different styles of side-marker light emblems. Two are referred to as denoting “early” and “late” production emblems. Early production cars used a foil emblem, while later cars received a cast bezel that read simply “427” with no SS, and had a black background. The emblem shown on Gordy’s car makes it an early production car. A third style has been seen on Canadian-spec cars, and is similar to the late style, but has a red background.

The “Big” Option

The engine in this car is the 385-horsepower version that has been rebuilt as close to factory specs as possible. The .030-inch overbore supports cast, TRW pistons creating a 10.2:1 compression ratio. In factory form, the L36 427 engine featured a camshaft with a duration of 214/218 at .050-inch lift. Valve lift was a conservative .461/.480-inch. The replacement specs out at .461/.480-inch lift, and 268/274 degrees duration at .008-inch lift. The cast, oval-port heads support the stock intake and Quadrajet carburetor. Behind that is the aforementioned Turbo 400 connected to a Posi-filled 12-bolt with 3.08 gears. The combination makes this a true, muscle-bound family cruiser.

“There were 1,778 Impalas produced with the SS427 option, but no one knows for certain how many of them were convertibles. The best guess is roughly 10-percent,” Gordy said. You would think that such a low production-number would relegate this car to museum status, but Gordy doesn’t keep it tucked away. Sure, he is selective about where and when it hits the road, but when it does, you can bet he and his wife are definitely enjoying the ride. That’s because, as Gordy said, girls like convertibles.

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About the author

Randy Bolig

Randy Bolig has been working on cars and has been involved in the hobby ever since he bought his first car when he was only 14 years old. His passion for performance got him noticed by many locals, and he began helping them modify their vehicles.
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