C3 Buyers GuideThe C3 Corvette might be the most controversial model of all the generations Chevrolet has produced. If ever there was a GM show car, with all it’s impracticality transitioned to production, it was these late 1960’s and ’70s Corvettes. The C3 also had the unfortunate task of being released on the heels of the C2 Corvette, and understandably, was a tough act to follow.

The 1968 Stingray (all one word now, as opposed to the C2’s Sting Ray,) was based heavily on the Mako Shark II concept car that wowed folks in 1965. It’s amazing to think that these show cars are 50 years old!

There were two Mako Sharks, one a functional driver and the other a pusher that was usually featured in Chevrolet publicity material of the day. The paint scheme was blue and gray on top and silver and white along the rocker panels, and the result of GM Styling guru Bill Mitchell’s fascination with marine animals. In retrospect, not only was Mitchell a talented visionary, but turns out he was a pioneer of biomimicry in the field of automotive design.

In 1969 the Mako Shark II morphed into the Manta Ray. When viewed today, its clear that it influenced the design of soft-bumpered, production Corvettes that would later debut in the early ’70s. The C3 surrendered the comparative practicality of mid-year Corvettes (especially the coupe) for a longer, heavier, model with storage space that would barley accommodate a six-pack of beer and a couple of eight-track tapes.

Regardless, when the sleek new C3 debuted in the fall of 1967, all those shortcomings were overlooked. Low-slung with peaked fenders and a pinched waist that simultaneously evoked a coke bottle, a shark, and the hourglass curves of a woman’s body, it has become one of the most enduring automotive designs ever produced and still looks fresh today. It also had concealed headlights and windshield wipers, fiber optic blinking lights, and a sugar-scoop rear window. The new C3 generation also introduced removable roof panels, a modern automatic transmission, and all the heavy duty horsepower Chevrolet could muster.

They say an icon perfectly mirrors its time in pop culture and the C3 Corvette did just that. Over its 14 year production run, it reflected the best and worst of the automobile industry. From fire breathing early models, to the emission-controlled, luxury GTs they transformed into near the end of their production run, the Corvette exactly reflected the tenor of the times while surviving bean counters, stringent governmental regulations, and foreign competition.

In retrospect, the C3’s production run went too long, and by 1982, it was obsolete by modern car standards. This factor, more than anything has been detrimental to the legacy of the C3. If the model run had only been half as long, and replaced by a new model in the mid-’70s, the suddenly long in tooth Shark (even by 1970’s standards) would have been spared the embarrassment of aging badly. Commensurately, these later year C3’s have become the brunt of jokes from detractors and other Corvette skeptics.

Hindsight has the uncanny ability to clarify perception and now the lowly C3, especially later rubber bumper models, emerge as the last of the Golden Era of Bill Mitchell design and really lend themselves to the resto-rod movement. For example, a 1975 Corvette is old enough to be smog exempt and with a crate motor and suspension upgrades, is an awesome DIY project. C3’s are also a great way to enter the Corvette hobby. We love all versions of the C3, and for a lot ‘Vette enthusiasts, it’s the pinnacle of Corvette cool.

A  brief overview of this most-produced Corvette generation is daunting, so we have broken it down to four sections, 1968-1972, 1973-1977, 1978-1979, 1980-1982. While all models utilized the carried over the independent rear suspension chassis and disc brakes from the C2.  Every Shark shares doors, windshields and T-tops. Where they differ is front and rear end styling tweaks, roof design, fender vent design, and chrome or rubber bumpers. Let’s not forget the performance factor, either. From a 427 CI V8 in 1968 to a 305 CI weezer motor in 1980, the C3 has seen every possible combination of Chevy power.

HERE’S A CHEAT SHEET OF THINGS TO CONSIDER WHEN PURCHASING A C3 CORVETTE

FRAME RUST – Corvette bodies don’t rust but that doesn’t mean their steel frames don’t. Always insist that any car you’re interested is lifted up on a hoist so you can poke around under the body and check for corrosion. Now is the time to check for damage as well as frame integrity. Be sure and check where the trailing arms of the rear suspension connect at frame kick-up. They can gather dirt and debris are prone to rust. While the car is up in the air, also do a visual check on the internal side of body panels, too.

BIRDCAGE RUST – The new for 1968 Corvette Coupe continued the use of a steel sub structure nick named the “Birdcage,” which looks like a steel windshield frame married to a roll bar. The new coupe had revolutionary T-tops with a center bar replacing cross braces at the windows. The roadster makes due with a metal windshield and cowling braces. Make sure you know the condition of this steel substructure, especially at the bottom of windshield posts.

T-TOP ISSUES – Inspect latches and weather-stripping of T-Top equipped cars. They can be fussy,leak and creak. A weather strip kit from a myriad of aftermarket suppliers and tweaking latch tightness will solve most problems. Glass tops on later models can be prone to cracking.

HIDDEN HEADLIGHTS –  The C3 utilizes vacuum operated headlight doors and on early models, windshield wiper cover. This system is susceptible to leaks and other maladies. When working, it is fairly reliable however, relies on a labyrinth of hoses, valves and actuators.

DISC BRAKES – C3’s use four-wheel disc brakes inherited from the C2. The system is prone to corrosion in the lines and calipers, which led to an aftermarket niche to replace susceptible parts with stainless steel components. Make sure you check out the brake system as it is expensive to correct.

CHECK BONDING STRIPS – Corvettes are made like a jigsaw puzzle with many pieces connected by lengths of fiberglass called bonding strips. If a car has been repaired you can easily see where the damaged material was removed. Also look for smoother finished interior panels as a sign that the car has been in an accident. Not really a deal breaker, but more important, that the damage was repaired correctly.

INDEPENDENT REAR SUSPENSIONThe C3 carried over the independent rear suspension from the C2 and brought along similar complexity and maintenance issues. There are U-joints, half-shafts and trailing arms that need to be tweaked, aligned, and looked after to function properly and to last under hard driving (which most Corvettes have seen in their lifetime).

CHECK ALIGNMENT OF DOORS, HOOD, TRUNK AND BUMPERS, WINDSHIELD WIPER AND HEADLIGHT DOORS – Wide or uneven gaps in body panels, misaligned bumpers, and mismatched paint are signs a car has been repaired. Again, not the end of the world, but to fix a car that was repaired improperly can be expensive. The 1968-1972 models have a vacuum-operated cover over the windshield wipers that can be tricky to align.

CHECK FOR STRESS CRACKS – Fiberglass ages differently than steel, and all Corvettes of this era suffer from stress cracks. Look around windshield posts, panel cut-outs and wheel-well lip areas for tell-tale signs of wear-related stress cracks.

RUBBER BUMPERS – C3’s from 1973-1982 pioneered the use of plastic skin bumpers. The technology was embryonic and has a tendency to disintegrate after years of exposure to UV rays. There are replacements available but the process is labor intensive to fit and match paint.

MAKE SURE THE CAR IS COMPLETE AND ORIGINAL AS POSSIBLE – A matching numbers car, i.e. VIN and the engine serial number match, is worth roughly 20 to 30 percent more than an altered car. This number matching standard was birthed by fussy National Corvette Restorers Society judges and has been deemed to be the highest integrity a Corvette can have. We agree, but there might be a good buy with a non-matching number drivetrain out there that could be a great car to own and enjoy, so don’t let the matching numbers mandate scare you. The good news is that there is a vast Corvette aftermarket supplier base that would love to help you restore your mid-year Corvette. Also, as a general rule, a color change is a deal-breaker for a lot of folks, so find a car that is painted in a factory color that turns you on.

VERIFY MOTOR AND VIN NUMBERS – This is fairly easy to do. Some research is required to get up to speed on VIN and engine codes, but definitive guides are widely available.

GET A USED CAR CHECK – The Corvette is exotic, but isn’t immune from mere mortal system checks. Check fluids, do a compression test, check the cooling and electrical systems, check the brakes, steering linkage, and other common safety items so when you drive home you don’t end up in a ditch. If you can do this yourself, great, if not hire a reputable mechanic; preferably one who is familiar with Corvettes. While you’re at it, check every single light, knob, blinker, speaker, etc., to see what’s working and what isn’t. If you really want to be thorough, hire a ‘Vette guru who can give you a detailed report card on the car of your dreams. Money well spent, we think.

TEST DRIVE – This is a must. Be careful not to let the owner run a monologue about the car as you  drive. Turn off the radio and take the car on side roads and the freeway. Take note of any clunks, smoke, valve train noise, or sloppiness in the steering, transmission, or brakes.

TAKE YOUR TIME – Chevrolet built nearly 500,000 C3 Corvettes! Most have survived. Take your time, look around and don’t buy the first car you see.

ANTICIPATE OWNERSHIP COSTS – You’ve got to store, insure, and maintain a 40-year old automobile. Create a tally of what your monthly costs will be to participate in the Corvette hobby without going broke.

GET EDUCATED -The scope of this article is a broad overview of the C3 Vette model run. We strongly suggest reviewing several Corvette “Bibles” to thoroughly educate yourself on rare options, colors and production numbers.  Corvette Online has researched the best of them for you here.

WELL SERVED BY AFTERMARKET – Check out Zip, Corvette Central, Eckler’s and Mid America Motorworks for extensive selection of parts and mods.

Model Years 1968-1972

These models are the holy grail of the C3 production run. They have undiluted Mako Shark show-car styling, no emission controls or safety bumpers, and came from the factory with motors ranging from mild small-blocks to hairy, tri-power big blocks. They are the last of the golden era of Detroit muscle and are coveted by collectors.

Corvettes between 1968-’69 cars can be distinguished by four vertical vents on the front fenders, no fender flares  and round exhaust tips. Model years 1970-1972 are distinguished by cross-hatch fender vents, fender flares and rectangular exhaust cutouts.

The late 1960’s saw engine displacement as a badge of honor and Corvette kept up the pace. In 1970, the 327 CID jumped to 350 CID and big block motors increased from 427 CI to 454 CI. Horsepower reached a zenith of 460 horsepower from the big rat motors during these years, but by 1972, the government required power ratings to be rated  installed in the car, not with motor on dyno with open headers and no parasitic accessories attached.

Big blocks, L88’s, L89’s and LT1 small block V-8’s bring big money but a 300 horsepower small block car is a great driver and can still be had by mere mortals. Factory side exhaust, hardtops, and P02 full wheels covers add value as well. The C3 was a big hit in the marketplace and sold more than 130,000 units in it’s first five-year run. The best selling year goes to the 1969, over 37,000 units sold.

Model Years 1973-1977

These years retained the sugar scoop rear window but switched to urethane bumpers and single slot fender vents. The 1973 model was unique as it was the only year with a soft front end and chrome rear bumpers. Several milestones are noted in these years although not for the better. The end of the line for the factory big-block V-8 was 1974, 1975 was the last year of the roadster until 1986, and the 1976 has the dubious distinction of the only Corvette to sport a steering wheel lifted from the lowly Vega. Engine choices dwindled as well with the L-82 emerging as the hot engine.

Another trend came to the forefront in this era,the more luxury equipment (leather, automatic trans, air conditioning etc.) built into the C3, the better it sold. 4-speed manual transmissions accounted for less than ten percent of total production. Chevrolet delivered almost 50,ooo Corvettes in 1977 making it top seller of this series. Buyers loved the styling and bling and as long as it had an adequate V8, they snapped them up in droves. GM sold more than 200,000 C3s during this period.

Lastly,  Zora Arkus-Duntov retired in 1975 and Dave McClellan took over the coveted job of Corvette chief engineer. For the first time since 1953, the Corvette enterprise was helmed with new vision.

Model Years 1978-1979

After years in a holding pattern, Corvette was heavily refreshed for 1978. It sported a wraparound glass window that vastly improved storage capacity and evoked mid-year nostalgia as well. After years of unique interior components, the Corvette was updated from GM parts bin. The dash and console were new and now able to accommodate most GM audio equipment from the factory. The L-82 received bump in horsepower (to 220 hp) and low profile radial tires were available for the first time.

The big event of 1978 was the 25th Silver Anniversary and Indy Pace Car models. Not much more than a standard Corvette with two-tone paint and tape stripes, but they nonetheless took the market by storm in 1978. The replica Indy Pace Cars in particular, caused a stir when speculators artificially drive prices to double MSRP at the dealerships.

Basically a carryover year, 1979 saw the Pace Car’s clamshell seats become standard, and front and rear spoilers as regular production options.

The gamble to delay a redesigned Corvette for 1978 paid off for GM, which sold almost 100,000 units in these two years alone. Corvette production in 1979 nudged past the 50,000 unit mark for the first time. Not bad for a 10-year old design with amortized tooling.

Model Years 1980-1982

These were the swan song years for the C3. Front and rear styling was again revised with integrated spoilers and fender vents with a black grille. GM did an excellent job at keeping the Corvette compliant with federal bumper standards without screwing up the styling. The L-82 reached the end of the line in 1980, now with 230 horsepower. The 1980 Corvette is the poster child for C3 critics as it debuted the 180 horsepower 305 motor for one year only. We say this is the perfect ‘Vette to ditch the smog motor and swap in an LS crate motor and leave the naysayers behind in a cloud of molten rubber…

Another milestone in 1981 was production of the Corvette was moved to Bowling Green, Kentucky. The old St. Louis factory that churned out hundreds of thousands of Corvettes was run down, tired and closed by GM mid-year. The good news is the last half of the 1981 Corvette production run benefitted from new production line machinery at Bowling Green and generally have better body panel fit and paint than its predecessors. The last Corvette built in St. Louis was in August, 1981. Big news was a new, rear composite spring that was 33 lbs lighter and the one year only L81 V-8 produced a mere 190 hp.

The final year for the C3 was 1982 this final model year had every improvement that 14 years of evolution brings. While timid compared to todays Vette, these are nice riding and driving models. The unloved Cross-Fireinjection system debuted this year and was the first time since 1965 that FI could be had on a Corvette.  It was the only engine available that year and put out 200 horsepower mated to a new four-speed automatic transmission.

The Collector Edition was offered as the last of the series and featured special paint, a hatchback, and distinctive interior and wheels. Chevrolet kept the sales needle pegged and moved more than 102,000 units in three years.

The Clown Car Factor - C3's seem to have attracted more than its fare share of horrifying customization. We think the stock styling is hard to improve on. We're all for making your car a personal statement and hey, it's a free country. But maintaining the value of a C3 without adding fuel to the mullet car reputation is the best way to go.

What are these cars worth?

The collector car market fluctuates from year to year and is influenced by the economy and the whims of the hobby. The best way to ascertain what a C3 Corvette is worth is to find comparable cars for sale that are similar to a car you’re looking for. A keen buyer will scour Craigslist, Hemmings, AutoTrader, and other publications to see what cars are bringing. Auction houses like Barrett-Jackson and Mecum’s are good resources to monitor the fluctuation of value. Pro-Team Corvette is always a good barometer of what C3’s are worth.

Joining a Corvette club could be a valuable resource as well as online forums and chat rooms. The National Corvette Restorers Society is a also agreat resource too. As always, keep your eye on Corvette Online as well.

As a general rule, chrome bumpered cars bring the most money as they represent the last of the muscle car era. Big block motors (especially L-88’s and L-89’s,) and later models like the 1974 big-block, 1975 Convertible, 1978 Pace Car and Silver Anniversary, and ’82 Collector Edition come to the fore as most desirable models. Rubber bumpered Sharks probably will never bring as much as a chrome bumpered car but that’s precisely why they’re cool cars for the rest of us.

Finally, the quality of the car is an  important factor in determining value, but color and options are critical factors as well.

Documentation can really add value to the car as well. Brochures, bill of sale, factory owner’s manuals and maintenance receipts can substantiate originality and provenance. Original cars are also worth a premium as many ‘Vette aficionados stand by the old mantra, “they’re only original once.”

We think the three speed Turb0-Hydramatic was introduced in 1968 is well suited to the ‘Vette. Most ’68-’72 Vettes are equipped with  manual transmissions, but by the end of the model un in ’82 most were automatics. Some non-original, non-matching numbers cars cars would make good drivers and might be good values, so don’t overlook one in good condition.

Ultimately, the goal is to take your time, exercise due diligence by researching online, talking to Corvette club members, or hiring an expert to suss out good cars from bad. Happy hunting!