This engine layout, used e.g. since 1953 in the 1.5-litre Porsche 550 and Porsche 718 sportscars, seldom made its way into larger Grand Tourers, which were accepted to race as such only if a minimum production run had been completed: not a single manufacturer was keen on making a big investment to build cars "at a minimum rate of one hundred identical units as far as mechanical parts and coachwork are concerned in 12 consecutive months",[4] as required by the FIA, without having the necessary experience with such applications and the right components.

[9] The coachwork, designed by John Frayling and made by FRP, had its own features such as reduced overhangs, Kamm-tail, roof-integrated engine air intake and special doors which extended into the roof to give the drivers greater access to the cockpit once they were open,[clarify] an idea that was kept on the car's successor, the Ford GT40.

[9] The prototype car (chassis LGT-P, steel monocoque) was shown to the public in January 1963 at the UK Olympia Racing Car Show, making a big success and provoking great expectations,[2] and during the following months South African Tony Maggs raced it at Silverstone (finishing fifth after starting last on the grid) and at the Nürburgring 1000 km (retiring for technical reasons).

[9] Understanding the potential performance of the Mk6, the Ford Motor Company bought it so as to further test its capabilities,[10] laying the foundation for its GT40 project and involving Broadley himself, although he later left the program.

Replaced by a Traco-tuned 6 L (370 cu in) Chevrolet V8 delivering 530 hp (395 kW) at 6500 rpm, the car was extensively raced in North America and won the 1963 Bahamas Speed Week[12]