Designed by Ferdinand ‘Butzi’ Porsche — the force behind the wildly-iconic 901/911 — the 904 GTS was Porsche’s first model to get aerodynamic fiberglass bodywork and was powered by the same mid-mounted, 180hp, air-cooled, quad-cam, opposed four-cylinder engine from the 356 Carrera. Of the fewer than 110 units produced in ’64 and ’65, a few specimens from the end of the run were fitted with six-cylinder engines from the 904’s successor: the 906.
Despite the immense rarity of six-cylinder 904s, RM Sotheby’s is now offering up a stunning 904 example with the seldom-seen six-banger. After leaving the factory in March of ’64, this example was raced in the late ‘60s and early ‘70s before undergoing a restoration in 1980. Around the turn of the millennium, this 904 was repainted in Silver Metallic and fitted with a black leather interior. Because the original four-cylinder engine was damaged, it was replaced with a period-correct, 200hp, magnesium-cased, twin plug, 2.0L, six-cylinder Type 906 mill. Since then, the engine was restored to its factory-spec and is now being included in the sale of this 904, along with a myriad of historical documentation, and an extra set of rims. This ’64 904 is slated to cross the auction block at RM Sotheby’s upcoming Paris sale on February 5, 2020, where it’s expected to fetch between $1,775,000 and $1,997,000.