1966 Jaguar Mark X

The Jaguar Mark X (a.k.a. Mark Ten or 4.2) was the company's top-of-the-line saloon car from 1961 through 1970 (including being renamed the 420G in October of 1966 for the London Motor Show). It used a unitary body-shell, codenamed 'Zenith', and powered by the 3.8-liter, triple carbureted engine as fitted to the E-Type, giving it a top speed of 120 mph. Its design featured a slightly forward-leaning nose, four headlamps set into the rounded front fenders, and a vaned grille.

For the first time on a Jaguar saloon, there was an independent rear suspension sourced from the newly introduced E-Type sports model. During its production lifespan, the Mark X received numerous updates and modifications, including enhancements to its cooling system, heating, and air conditioning and an all-synchromesh gearbox became a feature. Power-assisted steering was standard on all the later 4.2 cars, along with a Thornton Power-Lok limited-slip differential.

In the United States, the mid-1960s Jaguar Mark X four-door sedan had a base price of approximately $7,000. The XK-E Roadster had a factory price of $5,400 and the Mark II Sedan listed for $5,420. The Mark II had a 107.4-inch wheelbase while the Mark X rested on a 120-inch platform. Powering the Mark II was a 3.8-liter six while the Mark X used the 4.2-liter engine. Both had a cast-iron head, aluminum-alloy head, solid valve lifters, and seven main bearings.

The Jaguar 420G was distinguished from the Mark X by the addition of a vertical central bar splitting the grille in two, a chrome stripe along the wing and door panels, and side indicator repeaters were located on the front wings. The interior clock was moved to a central position, air conditioning was optional, and the dashboard was padded.

by Daniel Vaughan | Aug 2020