In 1993 Porsche introduced the Type 993, which would be the last air-cooled 911 produced by the German company.

Developed to take part in national championship series in Europe, Japan, and the United States, the stripped down race cars were officially named the 911 Cup 3.8 RSR.

Customers could choose between three distinct factory-built 3.8-liter engines, each one tuned to a different specification.

Offered here is a very rare Guards Red 911 Cup 3.8 RSR, equipped with the original numbers-matching M64/75 engine.

Designed for endurance racing with a power output of 349 bhp, this highly tuned engine features a resonance intake system, six intake plenums with separate throttle valves, a different camshaft profile, and no catalytic converters.

Like most RSRs, the Porsche is also equipped with the type M50/34 close-ratio six-speed manual transaxle.

This outstanding RSR was originally delivered to Michael Doolin of Sandy, Utah, in July 1997.

Of the 45 examples built to 3.8 RSR specifi...