What's a Ford Thunderbird Mark T? Not produced at the factory, the Mark T was a 1971-1974 dealer-installed option package on the Ford Thunderbird that gave the car a number of features from the Lincoln Continental Mark Series. This was possible because the two cars shared, from 1969, the same basic platform; between 1969 and and 1971 the 'Glamorbird' Thunderbirds and the Lincoln Continental Mark III had a lot in common, and from 1972 onwards the 'Big Bird' Thunderbirds and the Lincoln Continental Mark IV were almost identical.
A 1971 Ford Thunderbird Mark T had a Lincoln grille (but bearing a 'Mark T' badge), a custom bumper to fit it, and a custom hood and grille header panel to fit the changed grille size and shape. A new vinyl roof in the Lincoln pattern vinyl was fitted with a new chromed molding at the base of the C pillar. The interior and all other features were stock Thunderbird.
1972-74 Mark Ts had similar changes with the addition of a Lincoln-style faux spare tire cover on the rear deck lid, but this was not the Lincoln part; the Mark T version was smaller. Where on the Lincoln the word CONTINENTAL was laid out along the curved line of the simulated spare, the Mark T had THUNDERBIRD in chromed letters instead.
Very, very few Mark T cars exist. Only one 1971 Mark T is known to survive, and a few of the subsequent years. It is not known who produced the custom parts package, or what dealers offered it. If you find one, you truly have a car that is, as the Thunderbird ads used to say, unique in all the world. | 
