1976 Chevrolet Corvette C3

The 1976 Corvette offered here was part of a converted two-car showcase by Hungarian resto-mod specialists, Protourergarage. Formed in Budapest 10 years ago by two friends and business partners, the pair decided to start building pro-touring Corvettes in Europe, having visited (and canvassed) showgoers at the Specialty Equipment Market Association in Las Vegas as to their requirements.

After nearly half a decade of research and investment, two C3 Corvette coupes, serving as proof-of-concept vehicles were modified, retaining the body shell of the original cars, but with later Corvette underpinnings. The car for sale today is the earlier of the two conversions – a C3 built with a chassis containing C3 and C5 hardware, together with an LS1 V8 and a six-speed transaxle from a C6 Corvette. Since completion, it has covered less than 2000 kilometres, registered as a tax-exempt historic vehicle in the UK.

The chassis, built to Protourergarage’s own design, used QA1 coil over suspension all round; the original chassis and running gear, delivered to the workshops in very poor condition, was discarded, but the body was repaired and uprated to fit the new chassis and running gear. Its sister car, sprayed grey, featured C6 hardware more prominently in the chassis, and had a more powerful engine than the car offered here; in fact, it placed seventh in the 2016 Tuning World competition in Bodensee, Austria, whittled down from 30,000 initial entrants.

The vendor, Protourergarage’s co-founder, has since watched the company convert around 100 more Corvettes to customer specifications; he’s keeping the award-winning C3, and another C2/C6 resto-mod currently in build. This car represents the very start of Protourergarage’s journey, and he’s justifiably proud of what the firm set out to achieve.

Outwardly, the car for sale may resemble a C3 Corvette, but its fibreglass bodyshell has been subtly altered (with extra fibreglass let in) to accept the wider C5 track and fatter (18x9.5 and 19x12-inch) wheels from a C6 Corvette Centennial Edition. Painted gloss black with black centres, it’s a far cry from the 15x8-inch Rally wheels it originally wore. Said wheels appear free from kerb rash and scuffs.

All brightwork, including the door handles, was repainted in black, along with the outer sill kick panels.

Originally red, the car was resprayed as part of its rebuild in Ford Tangerine Scream Pearl, a colour available on European Focus STs between 2012 and 2019. The vendor noticed (and liked) the shade as it appeared on a colleague’s car in Hungary; wanting the Corvette to stand out as a promotional vehicle, had it painted in the same colour.

As a result, the paint finish is rather better than what the Corvette St. Louis plant managed in period; one of the reasons Corvette production moved to Kentucky in 1981 was owing to its booths unable to spray certain shades and mixes.

Around the car, the panel fit and gelcoat surfaces appear excellent; the car retains its single piece moulded rear bumper that became standard fit in 1975 – earlier cars used two piece items with a faint moulding line visible in their centre. Crucially, there are no cracks or stress fractures around vulnerable parts of the car. The fibreglass around its pop-up headlight nacelles, door jambs, filler cap surround and taillight cut outs are smooth and unrippled.

The only visual demerits can be found in the door apertures themselves; on either side, the rocker panels have had paint chipped off from the doors opening and closing, with the worst of the chips appearing on the nearside.

Again, a departure from what the Corvette left St. Louis with. Fully retrimmed in house, the car was fitted with Dakota aftermarket gauges and a Retrosound radio, faired in to fit the factory nacelles and aperture. The dashboard, a new item, is free from cracks and splits; the same is true of the centre console, whose shift boot and gearstick now stir a C6 six-speed manual gearbox.

A clean looking Momo Prototipo steering wheel is fitted with the upper half of the GM adjustable column retained. Leather trimmed A pillar inserts keep the factory VIN position; yellow contrasting stitching runs across the dash and door trims.

The standard, removable ‘T-Tops’ have been kept, their supporting centre frame and locking mechanisms working as intended, with an absence of rips or tears on the panels. The outer edge of the windscreen where the panels sit appears excellent, and it’s a similar story at the rear, although the head of one screw in the central spar of the roof support has tarnished. Standard pedal rubbers are fitted - and look as if they’re new. All door seals and weatherstripping was replaced in the 2016 rebuild.

The Corvette’s seats were also redone as part of the transformation in matching leather, with the same contrasting yellow stitching along the upper and lower cushions, and outer edges. The seats present well, with no wear apparent on the cushions or bolsters.

Under the bonnet, a low-mileage, fully rebuilt LS1, delivered to Hungary from a donor vehicle in the United States, sits where the car’s original 5.7-litre, 180 bhp, L48 once lived. The reinforced metal supports around the engine, custom-made by Protourergarage, are clean and free from rust; engine levels are where they should with no weeps or leaks from gaskets. Free-flowing exhaust headers were fitted to the engine to lift power output to a quoted 380bhp; while the pipes themselves look immaculate and free from discolouration; the mating points of the manifolds have surface rust where they attach either side of the block.

The Protourerarage hybrid chassis is as it left the works in Budapest in 2016, appearing fresh and straight with only the most minor surface corrosion on bolt heads. There are tiny scuffs on the underside of the front bumper; the u-clamps holding the anti-roll bars fore and aft are slightly discoloured.

The works’ powder coating means that the chassis perimeters present as fresh and clean, with the steel floor pans and fibreglass bulkheads in similarly excellent outward condition. The front-mounted radiator presents well, with no cracks or split vanes. The body mounts and steel support framework, critical rust traps on C3s, are well protected and appear rust-free. There is some surface rust on the transverse mid-section that the twin exhaust downpipes pass through, while the twin rear Magnaflow back boxes are show only mild discolouration from limited use. Mechanically, the car’s low mileage is apparent from the clean coil overs and C6 Z51 brake rotors, which have barely seen any use.

There are no leaks from the LS1’s sump or rear-mounted transaxle, the latter presenting as box fresh with its GM factory tag still visible. Its inner boots are clean, with no signs of cracking.

Pro-Touring conversion – Protourergarage – 2016

While not for purists, the Corvette for sale offers a fascinating blend of modernity and heritage. C5s are well-established as modern classics; many are still used as daily drivers and taken on track days on weekends. While a well-preserved C3 is a rewarding drive, Protourergarage’s C3 combines classic Bill Mitchell styling with bullet-proof and responsive C5 running gear, without the bulk and complication of the later car, which sometimes struggles on UK roads. This is, effectively, a new car that looks old, registered as a historic vehicle with an award-winning pedigree behind it. Use – and enjoy.

Our estimate for this car is £30,000 - £50,000.

Viewing is always encouraged, and this car is located at our headquarters near Abingdon; we are open weekdays between 9am-5pm, so to arrange an appointment please use the ‘Contact Seller’ button at the top of the listing. Feel free to ask any questions or make observations in the comments section below or try our ‘Frequently Asked Questions’.