Buyer’s guide: Chevrolet Corvette C3

| 26 Jul 2019
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Why you’d want a Chevrolet Corvette C3

Bill Mitchell and Zora Arkus-Duntov developed the C3 from Larry Shinoda’s stunning Mako Shark II, abandoning costly plans for the ’Vette to go mid-engined. Instead, they turned the concept into Chevrolet’s most striking – and enduring – shape yet, with those distinctive bulging arches and front wings that swept up from the engine bay to the wheelarch lips. 

The C3 Corvette would sell spectacularly well and could be a fun and exciting sports car. But European buyers attracted by the shape may well do a double-take at a far-from-tiny two-seater built into the 1980s without an opening bootlid, as well as with a separate chassis sitting on transverse leaf spring rear suspension. The late C3 gained a hatch, but Chevrolet persists with transverse leaf (in clever composite form) to this day.

Pre-1972 Corvettes had the most power, because unleaded-fuel capability and then catalytic converters sapped output dramatically as the ’70s progressed. Many later cars have since been uprated, however, or can be if you so desire. Big-blocks are the most sought-after in the USA, but in Europe – where fuel is costlier and roads are twistier – they can be a handful. A well-tuned small-block can match their performance while delivering a much more forgiving ride.

Though in some ways the Corvette may seem primitive, it had its share of innovative features. These included fibreoptic cables from the lights to a dash panel to show if any bulbs have failed, and warning lights for unfastened seatbelts, open doors and low fuel level in the 16½ gallon tank.

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

(l-r) Collector Edition of ’82 featured a hatch plus T-top roof; early-model C3 Corvette sported slim chrome bumpers

For the buyer, the shell and chassis are the biggest cost factors. Glassfibre bodywork may not rust, but it can suffer all kinds of damage. Getting rid of crazing, stars, ripples, cracks in the wheelarches and paint shrinkage can easily lead to bills of £5-10,000 in severe cases, to get it back to a perfect surface and paint finish. 

Plus, the steelwork is quite extensive and rust-prone – not just the chassis but the door frames and the ‘birdcage’ that links the sills, door posts, screens and roof bridge can rot severely. Remove trim panels where possible to check, and feel inside the chassis legs. Fixing a seriously corroded structure will inevitably lead to a massive bill. 

Check also that the car and its panels sit square and well-aligned – if not, it may be distorted from collision damage. Never buy unseen unless you can send a trusted expert to check a car – Corvette forums can help you to find a local guru.

Images: Tony Baker


Chevrolet Corvette C3: what to look for

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Bodywork

See above for trouble spots

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Engine

Hydraulic tappets were fitted on all but top-spec big-block and LT-1 350 engines. Check for smoke on start-up when revved, indicating wear – if it goes away when warm, it may just be valve seals. Inspect for oil leaks, many of which may mean engine-out to fix, especially from the rear crank seal. This car has a much later injected V8.

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Coolant

Look for oil in coolant indicating head-gasket issues, and for leaks. Cooling was marginal on big-blocks: a good radiator core and healthy shroud for fans help.

Originality

Tag on driver’s-door post will confirm if paint/trim are factory. Compare VIN tag on LH ’screen pillar with VIN-derivative number on block in front of RH head.

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Gearbox

Make sure automatics kick down swiftly and change gear smoothly. The manual shift should be light and precise: feel for jumping out of gear and weak synchros.

Steering

Worn steering shows up as a shimmy and reluctance to self-centre. Check bushes for wear, dampers for weakness, calipers for leaking and tyres for age.

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Interior

Seats (vinyl at first, leather later) are hard-wearing but centre console/dash are prone to cracks and door cards get damaged. Feel carpets for dampness.

Exterior

Assess panels for even and consistent alignment and gaps. Ensure that lights rise smoothly and fully – it’s normal for them to shake a bit when driving.


Chevrolet Corvette C3: on the road

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Neatly integrated energy-absorbing, 5mph bumpers came in from ’73 at front – along with radial tyres! – and ’74 at back; 1976 was last year of Stingray name

Once you’ve established that the engine fitted is the correct spec – or is the type that you want – and that all fluids are the correct colour and level, fire it up and look for smoke from the exhaust. After a good run, long enough to ensure that the car performs as it should for its engine tune, leave it idling and check under the bonnet for oil and coolant leaks, and signs of overheating. 

While a 6000-mile interval was required when new, specialists now advise an oil change every 3000 miles, especially on little-used cars; look and ask for evidence of regular attention. Well-maintained V8s will easily cover 150-200,000 miles before needing major work, and are cheaper to rebuild than most European engines.

The test drive should be carried out with the roof panels on (for a coupe) or the top up (convertible) because you will hear untoward noises from the drivetrain more easily. Make sure that all the electrics work and listen for excessive wind noise, indicating new seals are needed.

Power steering is a desirable option, especially on big-block versions, which, because of the bulkier lump, are distinctly heavy without it.

A wide choice of rear-axle ratios was available, so it’s worth finding out which is in the car that you’re viewing; the 3.08:1 final drive is most favoured for relaxed cruising.

The brakes should pull up straight and feel powerful – if not, it’s likely that one or more calipers are leaking and drawing in air, common on C3s. Too hard a pedal and weak performance suggest a failing servo; a pedal that sinks slowly to the floor betrays worn caliper seals.


Chevrolet Corvette C3 price guide

1975-'82

  • Show: £20,000
  • Average: £12,000
  • Restoration: £5000

 

1968-'74 coupé

  • Show: £25,000
  • Average: £15,000
  • Restoration: £7000

 

1968-75 convertible

  • Show: £32,000
  • Average: £20,000
  • Restoration: £10,000

Chevrolet Corvette C3 history

1968 C3 arrives: T-top removable panels; 327cu in (5.4) V8 in two states of tune; 427 (7.0) in three

1969 350cu in (5.7) small-block replaces 327, Stingray name added, 8in wide wheels

1970 LT-1 small-block (370bhp) and 454cu in (7.4) big-block (to ’74), 4-speed manual replaces 3-speed, egg-crate grilles, custom interior option

1971 Unleaded fuel capability hits power outputs

1972 End of LT-1 engine, chrome front bumper, removable rear window, wiper flap

1975 Catalytic converter (ZQ3 165bhp, L-82 185bhp), black plastic grilles, last convertibles

1977 T10 manual gearbox replaces Muncie

1978 Fastback rear window change; Indy 500 Pace Car and Silver Anniversary (glass T-top) 

1979 Optional front/rear spoilers and glass T-top 

1980 Weight reduced, 85mph speedo, last L-82

1981 Final manual transmission cars; 7lb glassfibre rear spring replaces 48lb steel item

1982 New cross-fire injected L-83, 4sp automatic overdrive ’box, Collector Edition with rear hatch


The owner’s view

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Owner Keith Perry’s C3 has the later LT4 fuel-injected 5.7-litre engine

“I bought the Corvette a year ago from Gateway Classic Cars, which has branches across the States,” explains owner Keith Perry. “I purchased it unseen – they’re a major company so I was confident that it would be okay. It’s original except it has the later LT4 fuel-injected 5.7-litre engine. 

“I’ve always liked American cars. When I was 21 I had my own tyre-fitting business and bought a ’69 Camaro Z28. It was an absolute blast; I wish I could find it now.

“For me, the C3 is the most classic Corvette shape. It turns heads everywhere and attracts lots of attention – driving it makes you feel younger!

“I have it maintained by AC Automotive in Shepherds Bush and I’ve bought a ’64 Corvair to keep it company. I’m changing the red rear indicators – I have amber ones on order.”


Also consider

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3
Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

Mercedes R107 (left) and Jaguar E-type are alternative buys

MERCEDES-BENZ R107

Though seen as a tourer, the R107 is a capable sporting car. With ‘sixes’ and V8s up to 5.6 litres, it matched most Corvettes for pace. Rot can be serious, but values are rising strongly.

Sold 1971-’89 • No. built 237,287 • Mpg 15-25 • 0-60mph 9.5-7.1 secs • Top speed 121-142mph • Price new £6189 (’73) • Price now £5-40,000+


JAGUAR E-TYPE SII/III

Equally eye-catching and offering similar performance with better handling, but cost much more in US when new. Rot is the main enemy, followed by engine rebuilds (notably V12).

Sold 1968-’75 • No. built 34,095 • Mpg 14-22 • 0-60mph 7.4-6.4 secs • Top speed 135-150mph • Price new £3924 (fhc, ’73) • Price now £20-100,000


Chevrolet Corvette C3: the Classic & Sports Car verdict

Classic & Sports Car – Buyer’s guide: Chevrolet Corvette C3

’Vette looks spot-on with wide steels and General Grabber radials; alloys were optional from ’76

The C3 has been the affordable classic Corvette for long enough, but they’re soaring in price. Be extra careful: there are plenty of tarted-up neglected examples around – check thoroughly for rust and for cars that are not what they claim to be.

Choose well and you can enjoy a reliable powerhouse that turns heads better than almost anything else in the price range. 

 

FOR 

  • Stunning, muscular looks
  • Exciting V8 soundtrack
  • Superb parts availability
  • Wide range of models to suit most tastes

 

AGAINST

  • Limited luggage space/accessibility
  • Big-block’s handling on bumpy, twisty roads
  • Gutless performance from catalysed, low-spec later versions

Chevrolet Corvette C3 specifications

  • Sold/number built 1968-’82/542,741
  • Construction glassfibre bodyshell bonded to steel birdcage, bolted to steel ladder chassis
  • Engine all-iron, ohv 5001/5359/5735/6997/ 7440cc V8, 1-3 twin-choke Rochester/Holley carbs; 165bhp @ 3800rpm-425bhp @ 5200rpm; 255lb ft @ 2000rpm-460lb ft @ 3600rpm
  • Transmission three- or four-speed manual or three-speed Turbo Hydra-matic auto (’82 four-speed 700-R4), driving rear wheels via LSD
  • Suspension: front twin wishbones, coil springs rear transverse leaf spring, trailing arms, transverse links; telescopic dampers, anti-roll bar
  • Steering recirculating ball, with optional power assistance, 3.6 turns lock-to-lock (manual)
  • Brakes 113/4in vented discs, with servo
  • Length 15ft 2in-15ft 5in (4623-4704mm) 
  • Width 5ft 81/4in (1733mm)
  • Height 4ft (1219mm)
  • Wheelbase 8ft 21/2in (2502mm)
  • Weight 2890-3534lb (1313-1606kg)
  • 0-60mph 8.9-6.4 secs
  • Top speed 125-151mph
  • Mpg 11-18
  • Price new £5400 (big-block, ’73) 

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