Envisioned as a luxury sports car, the Stag was designed to compete directly with the Mercedes-Benz SL class models.

To meet emission standards in the US, a key target market, the troublesome mechanical fuel injection was dropped in favour of dual Zenith-Stromberg 175 CDSE carburettors.

The various configurations Triumph envisaged would enable the production of four-, six-, and eight-cylinder power plants of capacity between 1.5 and 4 litres, sharing many parts, and hence offering economies of manufacturing scale and of mechanic training.

A number of iterations of Triumph's design went into production, notably a 2.0-litre slant four-cylinder engine used in the later Dolomite and TR7, and a variant manufactured by StanPart that was initially used in the Saab 99.

Installation testing of both the Triumph V8 and the Rover V8 was carried out in May/June 1967, the conclusion being that the engine was too tall and that front structure changes would be necessary.

Although later enthusiasts have shown that it can be made to fit the space, the decision to go with the Triumph V8 was probably more due to the Buick's lack of British sales experience, the fact that there was not a manual gearbox offered by Rover at the time, and that the different torque characteristics and weight would have entailed substantial re-engineering of the Stag when it was already behind schedule.

Furthermore, Rover, also owned by Leyland Motor Corporation at the time, could not necessarily have supplied the numbers of V8 engines required to match the anticipated production of the Stag.

[4] As in the 2000 model line, unitary construction was employed, as was fully independent suspension: MacPherson struts in front, semi-trailing arms at the rear.

A third cause of trouble was the engine's use of long, simplex roller link chains, which would first stretch and then often fail inside fewer than 25,000 miles (40,200 km), resulting in expensive damage.

Anecdotally, this arrangement was used to reduce production costs, as the cylinder head mounting studs and bolt were all accessible with the rocker covers fitted.

Finally, although pre-production engines were built meticulously, those fitted to production cars were not subject to the same careful quality control.

Engines are still being discovered with casting sand and core wire inside, blocking the coolant passages and causing overheating.

This combination of manufacturing and maintenance flaws led to some engine failures in the UK but in the US the situation was exacerbated by the need to fit low compression pistons to comply with California's low octane petrol requirements, and the associated advance in ignition timing to meet that country's continually changing emission regulations.

[7] British Leyland never materially re-engineered the Triumph 3.0 litre OHC V8 to address these issues, other than introducing a domed piston to aid combustion and a high-pressure cooling system that boiled over at a higher temperature.

Inside, Mk 2 cars had a slightly different warning light cluster and the instrument dial needles point up rather than down.

Very early production cars had a three-quarter window in the soft top, which was deleted during the 1972 model year as it tended to become trapped and then split when stowed.

Late Stags fitted with the slightly longer BW65 automatic transmission had a correspondingly shorter propshaft to compensate.

Electric windows, power steering and power-assisted brakes were standard with Delaney Gallay air conditioning being a factory fitted option.

A range of aftermarket products including a luggage rack, uprated Koni shock absorbers, floor mats, and Lucas Square Eight fog lamps were available as dealer-installed optional accessories.

British Leyland planned an equivalent model to follow the Stag in the form of a derivative of the Triumph TR7 sports car which was codenamed the Lynx.

The Lynx used the TR7 platform with an extra 12 inches in the wheelbase to accommodate a rear seat and had fastback coupe bodywork.

However the sudden closure of the Triumph factory in Speke, Liverpool, where the car was to be built and new policies implemented by BL's new chief executive, Michael Edwardes, led to the Lynx's cancellation.

This second car took very clear styling cues from the GT6, including the shape of the rear windows and roofline and the provision of air vent 'gills' in the C-pillar.

One Stag was reportedly fitted with the FF system by Triumph itself during development, but was either scrapped or converted back to standard specification.

Two more 4WD Stags were built in 1972 by FF Developments, a company separate from Ferguson that had licensed the technology for converting existing road cars.

Both had automatic locking differentials actuated by a viscous coupling and the same Dunlop Maxaret mechanical anti-lock braking system as used in the Jensen.