In 1965, only a discerning few customers ponied up for the top-of-the-line high-performance package on Ford’s iconic pony car. Popularly known as “K-code”—in reference to the special letter designation in the VIN of Mustangs so equipped—the package included a 289 cubic-inch V-8 engine rated at 271 horsepower and a medley of performance goodies for a whopping $442.60. Except for the $283.20 air conditioning, no other Mustang option had such an impact on buyer’s wallets, which meant that K-code production was understandably low.

The car’s solid-lifter V-8 was not the average Ford small-block. Inside its over-square, four-inch cylinder bores were high-strength flat-top aluminum pistons. These were linked via heavy-duty connecting rods with strengthened rod bolts to a more robust cast-iron crankshaft with an enhanced front counterweight to maintain high-rpm balance. Each cylinder head had enlarged intake and exhaust valves, while the engine breathed through cast-iron, header-type manifolds and into a standard dual exhaust system. A Special Handling Group helped make the most of all the power with heavy-duty shocks, springs, and a front sway bar.

Wearing a presentable older restoration, this K-code convertible is finished in its factory colors of Ivy Green over Black Crinkle Vinyl with a white convertible soft top. Crucially, this Mustang retains its numbers-matching 289 cubic-inch V-8 engine and is equipped with the desirable four-speed manual transmission. Even more interesting, while K-code Mustangs could not be optioned from the factory with air conditioning or power steering, this example has both. They are period correct and believed to have been dealer installed. Additional features include a power top, the Rally-Pac, a radio, and a console.

The car was fully restored in the early 2000s and still presents well. More recently, it was refurbished at a cost of more than $11,000. The work included replacing the fuel pump and lines, the dash, the sill plates, and window rollers, as well as professional detailing of the paint and brightwork.

A well-optioned, numbers-matching, K-code convertible, this early Mustang represents one of the most iconic and desirable examples of American performance, sure to be prized by Ford and muscle-car enthusiasts.