After ending its F1 and F2 program in 1962, Porsche refocused on sports car racing to bolster its road car lineup. To meet FIA homologation requirements, the Porsche 904 Carrera GTS was unveiled for the 1964 racing season, targeting international GT class competition.

Under Technical Director Dr. Hans Tomala, Porsche developed a lightweight steel box-section ladder chassis paired with fully independent double-wishbone, coil-spring suspension. Styled by Ferdinand Alexander “Butzi” Porsche, its fiberglass body featured a low-drag nose, sleek roofline, and an aerodynamic Kamm tail. Panels were manufactured by Heinkel aircraft and bonded to the chassis, enhancing rigidity and reducing weight. With a drag coefficient of 0.34 and a weight under 1,500 pounds, the 904 was among the lightest and most balanced sports cars of its time.

Although intending to use the six-cylinder Type 901 engine, delays led Porsche to fit the competition-proven Type 587 unit. The mid-mounted, 2.0-liter, four-cam, four-cylinder engine was mated with a five-speed gearbox, making the 904 capable of 160 mph.

Porsche built just 108 examples between 1963 and 1965 to meet FIA Group 3 regulations. Priced at DM 29,700 (around $7,425), the car achieved immediate success, winning its debut at the 1963 Targa Florio. In 1964, the 904 dominated the FIA’s two-liter GT class, earning a 24 Hours of Le Mans class victory, while helping Porsche secure the Manufacturers’ Championship.

Completed on February 27, 1964, this Porsche 904 Carrera GTS, chassis 904-028, was delivered to German racer Gerhard Koch through regional dealer Schultz in Düsseldorf. Finished in Silver Metallic over Blue, 904-028 was specified with seat belts and a sports exhaust.

Koch, a seasoned driver with a win over Jim Clark at Zandvoort and class wins at the Targa Florio and Nürburgring, excelled with 904-028, winning the Rheinland-Pfalz Trophy at the Nürburgring and placing 2nd Overall at the Grand Prix de Paris. Koch also campaigned the car in events such as the German GT Championship, Spa 500 Km, and the Angola Grand Prix, finishing 1st in Class and 3rd Overall behind two Ferrari 250 LMs.

At the end of 1964, Koch sold the car to fellow countryman and racer Rainer Ising. In 1965, Ising achieved significant results, including a 1st at Zolder and 3rd at Trier. Teamed with Bernd Degner, Ising secured an incredible 1st in Class and 3rd Overall finish at the grueling 82-Hour Marathon de la Route at the Nürburgring.

Following the 1965 season, Ising reportedly offered 904-028 for sale through the Porsche factory. By 1966, 904-028 is believed to have been imported into the US by Uwe Buehl, a former Porsche Works and Vasek Polak mechanic, for Pennsylvania-based privateer Roger Neuman. Neuman raced the car only twice before trading it back to Buehl, who sold it circa 1968 to Dieter Oest, a mechanic at Holbert Porsche-Audi in Philadelphia. An avid racer, Oest campaigned 904-028 primarily in SCCA events until early 1969, when 904-028 was retired from competition. Chassis 904-028 later returned to Buehl, who repainted it white and installed a type 901/05 six-cylinder engine, reportedly built to 906 specifications.

Circa 1972, Alexander Pollack, an architect and Porsche enthusiast from Ann Arbor, Michigan, purchased 904-028 after placing a want ad in Hemmings Motor News. During his remarkable 52-year ownership, Mr. Pollack maintained the car, driving it regularly and preserving its originality. Recommissioning work reportedly included a new dash top manufactured by 904 enthusiast Syd Baker, an engine rebuild by former Stoddard mechanic John Truman, and a repaint in its original Silver Metallic in the late 2000s.

Today, 904-028 is fitted with a 901/05 flat six-cylinder engine and 904 gearbox, and is accompanied by a manual, spare parts, tool roll, and assorted literature.

The Porsche also remains extraordinarily well preserved, retaining its original body, including its tail section, as well as seating surfaces, and a high degree of original components, according to an accompanying 47-page report by 904 historian and author Jerry Pantis. In this report, Mr. Pantis opines that 904-028 appears to be one of the most authentic examples in the world, placing it among the top 904s in existence.

With so many 904s damaged during racing, 904-028 differentiates itself with its originality, clear ownership history, and impressive racing career. It is a pinnacle example of Porsche’s engineering and competition heritage.