Fans of early Ford Mustangs should mark May 17 on their calendars as an original 1968 Ford Shelby GT500KR will cross the auction block at a Mecum sale taking place in Indianapolis.

The car, whose chassis number ends in 03397, is one of only two examples originally painted in a shade known as Special Light Orange. This one was kept in the U.S., having been first delivered to Courtesy Motors in Littleton, Colorado, while the other was shipped to the U.K. A copy of the original invoice is included with the sale.

Following on the success of the GT350 introduced for 1965, Shelby introduced the more potent GT500 for 1967, equipped with a 428-cubic-inch V-8 good for about 360 hp. Still not satisfied, Shelby upped the ante further for 1968 by introducing the GT500KR, otherwise known as the King of the Road.

It packed a Cobra Jet 428-cubic-inch V-8 together with a ram air intake, larger heads, and a revised intake manifold that combined to push output to some 400 hp. For insurance purposes, Ford claimed that the Cobra Jet 428 made just 335 hp, though even 400 hp may be a conservative estimate.

1968 Ford Shelby GT500KR - Photo credit: Mecum

1968 Ford Shelby GT500KR - Photo credit: Mecum

This car also comes with a 4-speed manual and its original hubcaps which were restored by expert Mustang restorer Timothy Lee. Its interior features black leather trim and woodgrain on the dash. A mileage figure isn't provided in the listing.

No estimate is provided either, though another 1968 example was sold at a Mecum auction last year for $160,000. Mecum also auctioned off a 1968 convertible example last year for $215,000.

Ford and Shelby eventually revived the GT500KR nameplate in 2008 using the fifth-generation Mustang. The modern GT500KR was introduced to celebrate the 40th anniversary of the original and came with a supercharged 5.4-liter V-8 good for 540 hp.