1972 MGB V8 Factory Prototype GT

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1972 MGB V8 Factory Prototype GT


MG’s original assessment of the possibility of a V8-powered MGB GT was stark: "We have investigated the possibility of installing the Rover V8 in the MGB and have determined the car would have to be widened at least 3-1/2 inches, obviously this is not feasible.” 

However, Ken Costello proved otherwise and, to his credit, he took one of his own cars to the MG factory to show them how he’d done it. The MG management and engineering teams were impressed, and according to an article published in volume IV, issue 2 of the MG V-8 newsletter of August 1996, Costello was unfazed by the thought of a factory car appearing, saying: "I'll keep on building them because it will take you two years to get into production"!

Costello’s willingness to share his expertise, along with the quality of the conversion, prompted Charles Griffin, British Leyland’s Director of Engineering, to give the go ahead to buy a Costello-converted MGB V8 to enable them to reverse-engineer a production car of its own. 

To this end, six standard 1800cc MGBs were pulled off the production line; half were right-hand-drive and half left-hand-drive. As 1972 MY vehicles, all were fitted with clear glass, hard plastic inner door pulls, navy blue vinyl seats with brushed nylon centre panels, and the ‘tapered slot’ steering wheel that was only fitted between August 1972 and June 1973. 

The changes were extensive and included modified engine mounts, reshaped inner wings and bulkhead, substantial changes to the steering column, re-siting the radiator, the installation of an oil cooler, upgrading the braking system, and re-engineering some of the engine’s ancillary components. 

But it was worth it, because the result was a fast, beautifully balanced car - but one whose launch coincided with the oil crisis of the early seventies. This, alongside the fact that BL didn’t want to MGB GT V8 to compete with the forthcoming TR7, meant that the ultimate MGB never really fulfilled its full sales potential.

The Vehicle

The car we are offering here is number 96, the fourth development example built, the first to use the chassis number prefix GD2D1, and one of the three original right-hand-drive models. The fate of one of the RHD development cars is unknown and as the other now lives in Australia the example we are offering here is the only one in the Northern hemisphere, so we expect it to draw a lot of interest.

After being used extensively for pre-production development and testing (including a high-speed run through France in the hands of Alec Hounslow and Mike Hearn during which it hit 138mph) it was kept at the factory and used for back-to-back testing against the first of the rubber-bumpered MGBs at places like MIRA. It is also said to still hold the unofficial factory record for posting the fastest time between Longbridge and Cowley, which probably isn’t something you’ll find in any official history of the company…

The vehicle was eventually released for sale to the general public after four grueling years, at which point it was snapped up Norman Ward, the son of Robert Ward, MG Cars’ plant director at the time. He bought the car on the 28th April 1976 for £875 - and then kept it for the next 32 years.

The car was then sold to its second owner, MG enthusiast Clive Wagerfield, who researched and documented the car’s history for the first time. It is thanks to his hard work and dedication that we are able to present such a comprehensive history!

On the Outside

Clive Wagerfield undertook a lot of remedial work to the structure of the car but chose to leave the bodywork and interior untouched as a tribute to the car’s originality and irreplaceable provenance. However, the current owner and vendor realised that what looked at first to be the original paintwork was actually a fairly poor-quality respray, freeing him to get the car sympathetically restored.

The work was entrusted to marque experts Frontline Developments in 2015. The Frontline team stripped the bodywork down to the bare metal before making structural repairs to the areas where the original metalwork was just too far gone to be saved. 

The doors were then carefully prepped before being restoring using liquid metal rather than the more usual reskinning (see video for details); the owner is painfully aware of the historical importance of this vehicle and went to great lengths to retain as much of the original fabric of the car as possible. 

The bodyshell and panels were then treated to a full respray in Glacier White to Frontline Development’s usual high standards. The car was then rebuilt paying attention to all the little details that make this car unique: the red commissioning plate, complete with the all-important ‘G23D’ prefix, was fastened back onto the front slam panel; the North American-spec petrol tank and vapour-return plumbing was reinstalled; and the one-off prototype radiator fitted after being re-cored. As a result, the car is utterly solid and looks terrific; if you know of Frontline Development’s work, then you’ll be familiar with just how good these guys are at what they do.

The underbonnet area still bears witness to its prototype status, with the changes that were made to the inner wings to allow the V8 to fit still visible. These changes take the form of a modified bulkhead, an ‘orange segment’ section cut out of the inner wing before being reverse welded back in place, and the top lip of the chassis rail being peened over to stop the oil feed pipe chaffing on it. 

The wheels are similarly interesting, and are believed to be the first sample set alloy wheels offered by Dunlop to MG for them to fit and evaluate on a running MGB V8 prototype.

And yet, the overall finish isn’t concours, because to make it so that would have been sacrilege. The car wears its history through its rich, hard-won patina; so, while the front grille is slightly dented in places, the owner felt that they’re an important part of the car’s history and should remain. For the same reason, the exterior brightwork was polished rather than re-chromed. 

The front over-riders were removed by the engineering team at some point in the car’s development to allow the fitment of auxiliary driving lights and no ‘V8’ badge was ever fitted, presumably to enable stealth testing to take place under cover of (relative) anonymity. 

Of course, the new owner could completely restore and replace all these items, but we hope he/she doesn’t…

On the Inside

The car was completely re-trimmed as part of its 2015 restoration. While the old seat fabric formed an important part of the car’s life, it was simply too far gone to be saved and reused. Similarly, new carpets were fitted as the old ones were badly worn. 

Everything else is original, including the instruments and the steering wheel, which have all been left unrestored. Interestingly, the latter is one of the short-lived and ill-fated ‘tapered slot’ wheels. These were found to be something of a liability as the tapered slot meant that drivers had the unfortunate - and somewhat alarming, one imagines - habit of getting jewellery trapped between the spokes… 


This is the only RHD MGB V8 to be fitted with a high-compression, US-specification ‘490’ series engine complete with a ‘49’ engine number prefix. The reason this is the only one is because while Rover was happy to supply MG with the engines it needed, it would only do so if it could ensure that the new sports car wasn’t going to be in direct competition with any of its own products and it felt the best way to ensure this would be to limit the supply of engines to the low-compression version that was fitted to the Range Rover rather than the more powerful engine fitted to its own high performance road cars.

Even the overdrive gearbox has a story to tell: legend has it that this is the very car that destroyed its gearbox in France during high-speed testing when the overdrive failed on 1st and 3rd gear, presumably due to issues with the amount of torque being transmitted through it. The solution was to strengthen the bottom gear by using 16 teeth rather than 17, and restricting the use of overdrive to 3rd and 4th gear only.

As a true factory development mule, this is something of a ‘bitsa’ car, with parts being taken off the shelf or fabricated as necessary. As an example, the front brakes caused some head scratching until the Frontline team realised that they’re actually from a contemporary Triumph!

Frontline Developments assessed the condition of each and every mechanical component during the car’s restoration, and found that most only needed a good service to bring them back to full health.

History Highlights

The importance of this car in the history of the MG heritage has been recognised over the years with a large number of website articles, owners’ forums, magazine features, marque books and even a DVD, a signed copy of which will come with the car.

The car also now wears its original number plate ‘MMO 229L’ with pride; an earlier DVLA error led to it being re-registered with another number in 2001. However, after intervention from the MG Car Club Ltd. who meticulously examined the car’s provenance before confirming its authenticity, the DVLA accepted the vehicle’s historic status and re-issued the original registration number in 2008.

See the full gallery below with over 500 photos, documents and videos demonstrating the car's history and provenance, including details of all restoration works.

What We Think

This car will appeal to serious collectors, investors with an eye to the car’s future value as well as MG enthusiasts; with an impeccable provenance and fully documented history, this is a very rare opportunity to own a piece of MG history.

The guide price is £30,000, and yes, we do know that this is twice the price of a very good production MGB GT V8 but this is a genuine one-of-a-kind car.

The car is with us at our headquarters in Abingdon and we would welcome potential bidders to come and examine the car for themselves. Please contact us to make an appointment.

Please note that there is an Auction Premium of 5% of the hammer price (plus VAT in UK & Europe only). Fees are minimum £600, maximum £6,000 (min Euro 720€/max 7,200€ & US$ min $500/max $5,000).

All vehicles must be collected within 7-days of the auction end. Storage fees of £180 + VAT apply (per car/per week) thereafter.

IMPORTANT: Please note that whilst Bonhams|Cars Online always strive to offer the most descriptive and transparent auction listings, we cannot claim they are complete analyses of any of the vehicles for sale. We offer the opportunity for bidders to view, or arrange inspections for each vehicle prior to bidding, and we encourage bidders to take advantage of this. We do look at those vehicles which are delivered to our premises for sale, but this gives our unbiased personal observations, not those of a qualified inspector or other professional. We do not formally test drive the cars.

Please also note that localised paint repairs are common with collectable and classic cars and if they have been professionally carried out then they may be impossible to detect, even if we see the car in person. So, unless we state otherwise, please assume that any vehicle could have had remedial bodywork at some point in its life.

Additionally, please note that most of the videos on our site have been recorded using cameras with standard microphones, which often result in inconsistent sound quality; in particular, engines and exhausts notes can sound a little different to how they are in reality.

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  • Location: Abingdon
  • Seller Type: Private
  • Odometer Reading: 83000
  • Engine: 3500
  • Gearbox: listings/auction-view.Manual
  • Colour: Glacier White
  • Interior: Blue Fabric

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