The LS6 engine RPO has been offered only once in Corvette history, and for only one model year—1971. With 454 cubic inches, a cast-iron block and aluminum heads, the first LS6 was second only to the full-blown L88 racing engine (offered from 1967 through 1969) in terms of both power and legend.

The original LS6 produced 425 horsepower and was the most powerful engine offered in 1971. Only 188 cars were produced with this power plant, less than 1% of Corvette’s 21,801 production run for 1971. The option price was $1,221, or 22% of the coupe’s $5,496 base price.

When tested by a leading automotive magazine, an LS6 with a four-speed manual and a 3.36:1 limited-slip differential produced impressive numbers: a 0-60 mph time of 5.3 seconds, a time of 13.8 seconds at 105 mph in the quarter-mile and fuel mileage between 9 and 14 mpg.

Building on the LS6 option was the ZR2 package. Priced at $1,747, the ZR2 included the LS6, a heavy-duty, close-ratio four-speed manual transmission, heavy-duty power brakes, transistorized ignition, lightweight aluminum radiator, special springs, shocks, and front and rear stabilizer bars. A total of only twelve ZR2-equipped Corvettes were produced, making them even rarer than the original Z06.

The ZR2 offered here is not only one of just twelve built; it is one of only two convertibles—and the only completely original one in existence. The car is untouched and has all of its original components.

The car won Gold at the Bloomington Corvette Corral in 1982 and Gold “Special Collection” at Bloomington in 1984. It is fully documented with warranty card, Protect-O-Plate, partial tank sticker, Delco Remy transistor ignition tag, Bloomington Gold Special Collection certificate, Corvette Owner’s Card and letter of congratulations from General Motors GM John Z. DeLorean.

SCM Analysis

Detailing

Vehicle:1971 454/425 ZR2 Convertible
Years Produced:1971
Number Produced:12 (two convertibles and ten coupes)
Original List Price:$7,672.80
SCM Valuation:$450,000-$550,000
Tune Up Cost:$400
Distributor Caps:$25
Chassis Number Location:Lower left windshield corner
Engine Number Location:Right front cylinder head deck
Club Info:National Corvette Restorers Society 6291 Day Road Cincinnati, OH 45252
Website:www.ncrs.org
Alternatives:1969 Corvette L88 roadster, 1965 Shelby 289 Cobra, 1965-66 Ferrari 275 GTS Spyder
Investment Grade:A

The car, Lot S118, sold for $466,400, including buyer’s premium, at Mecum’s auction in Monterey, CA, on August 14, 2010.

In the world of Corvettes, part numbers, production totals by model and RPO, casting numbers, assembly dates, and so on are quoted by almost all owners and aficionados. The word “rare” is spoken often—and appears in print when describing certain models, colors and options.

Well, here’s a really rare one for you: In 1971, General Motors built two RPO Corvette ZR2 convertibles. Besides the two 1969 ZL1 Corvettes (with the all-aluminum block, RPO L88), these 1971 ZR2 convertibles are the RAREST of all production Corvettes ever built—period!

So, why were only two of these cars built, and what makes them so unique?

First of all, the Corvette ZR2 option—on ten coupes and two convertibles—was only offered in 1971. Second, the option tacked $1,747.30 onto the convertible base price of $5,259, which immediately drove the cost up by 25%. To put this kind of money in perspective, the average yearly household income in the United States was $10,600 in 1971, and the average cost of a new house was $25,200.

What did the owners get for forking over so much cash? An aluminum head and intake; a 454/425-hp block; Heavy Duty dual-pin, power-assisted brakes; transistor ignition; a Muncie heavy-duty 4-speed transmission; special springs; huge shocks/sway bars; and a heavy-duty dual-disc clutch and flywheel combination.

Clearly, these Corvettes were not intended for daily driving, and Chevrolet’s sales literature made this clear to prospective buyers. Like the L88-powered monsters from 1967-69, keeping the engine cool was accomplished by going really fast—not stopping and sitting in traffic. These Corvettes were race cars.

To keep the weight down, no fan shroud was used. Giving up weight and maximizing performance were the reasons you could not get air conditioning, a radio or heater in your expensive new Corvette.

The history of an excellent buy

This ZR2 was ordered from Kluge Chevrolet in Bremerton, WA, with an MSRP of $7,276.80. It had four options: black leather ($158), the ZR2 package ($1,747.30), 4.11 Positraction ($12.65) and an auxiliary hard top ($273.85). It was financed through GMAC.

All that was a good bit of cash back in 1971, but this same ZR2 Corvette brought $466,400 at the Mecum Monterey auction on August, 14, 2010. I believe the car at this price was an excellent buy. The reasons are pretty simple:

This ZR2—remember it one of just two on the planet—is completely original. This convertible Corvette has its original engine, transmission, interior, rear end, glass, exhaust, tires, wheels, body panels and paint.

Its provenance is irrefutable, with the original Protect-O-Plate tank sheet, order copy and purchase documents. Added to that is a complete chain of title and owner history.

It received an NCRS Regional Top Flight award this year, and has accumulated several prior Bloomington awards.

The car has just 8,650 miles.

Finally, the second of the two 1971 ZR2 convertibles brought a higher price at auction—admittedly in 2008, when the Corvette market was stronger—even though it is not nearly as original as our subject car.

The other 1971 ZR2 convertible

The only other ZR2 convertible, chassis number 194677S117850, sold for $550,000 at Mecum’s St. Charles Auction on June 27, 2008. This Corvette also has documentation, but it was a race car in Europe in its early years.

This car returned to the U.S. in 1982. It came home with a small-block engine and is reputed to have been carrying racing wounds. When the tank sticker was uncovered, the new—and lucky—owner found out the true identity of his car. Nabers Brothers Restoration of Houston, TX, restored the car.

A very special car

The value and interest of our subject car goes beyond Corvette collectors to a wide range of auto enthusiasts. Although it was probably a Corvette person who bought this ultra-rare ZR2, I believe that it had an equal chance of being acquired by someone who would have added it to his collection of rare, unique, high-performance, race-ready cars. After all, there were only two built, and of the two, this is the only one that can claim to be original. Which, in the end, makes it one of one—the only original ZR2 on the planet.

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