The Jaguar XK 150 was the ultimate evolution of the XK platform—introduced with the XK 120 in 1948—and the XK 150 S 3.4, which arrived in 1957, was the model’s near-pinnacle. The use of three SU carburetors, a unique straight-port cylinder head, revised inlet manifolds, upgraded camshafts, and a lightened flywheel contributed to a raise in output to 250 horsepower, while four-wheel disc brakes provided stopping power that had been proven at Le Mans. The XK 150’s re-worked body design included a wider one-piece curved windscreen and thinner doors, providing greater interior space and comfort. Not entering production until 1958, the roadster variant featured roll-up windows to ensure optimal weather protection.

Completed on 26 June 1958, this XK 150 S 3.4 Roadster represented the top performance specification that year and left the Coventry, England factory destined for California. Finished with a black exterior over a red leather interior with a black hood, this Jaguar presents today with its original delivery colors. Significantly, the roadster further retains its matching-numbers engine, cylinder head, and body, according to the Jaguar Daimler Heritage Trust certificate on file. A reproduction owner’s manual, jack, jack spanner, T-handle “church key,” and grease gun will accompany this Jaguar upon sale. Furthermore, the roadster has been updated and modernized with a Tremec five-speed manual gearbox; the matching-numbers transmission has been retained and will also accompany the car at the time of sale.

In 2010, the XK 150 S was sent to XK’s Unlimited of San Luis Obispo, California for a restoration and reassembly. Photos documenting the work display the process of stripping the car of its mechanical components for rebuilding including the engine, transmission, brakes, and rear axle. Prior to this commission, the body work had been restored by a separate shop and was completed in August 2009. Invoices on file further detail the extent of the work, listing the total cost of the restoration in excess of $127,000. During the spring of 2020 a specialty shop in Scottsdale, Arizona performed additional service and maintenance to the cost of $3,148 as shown on two invoices.

Wonderfully restored with a matching-numbers engine and cylinder head and thoughtfully upgraded with a five-speed gearbox, this top-specification XK 150 S 3.4 roadster is a definitive classic, fit for a show field or a thrilling drive on tour.