Back in 1971, Lamborghini wowed the world with the Countach at the Geneva Motor Show.

Designed by Marcello Gandini, the flagship supercar marked the debut of the scissor doors, an iconic feature for Lambos to come, and represented a huge step forward in styling.

But its design wasn’t the only impressive novelty, as the Countach benefited from aircraft-grade aluminum body and used a tubular space frame chassis. This made it strong and light despite its size, and the Miura’s 4.0-liter V12 engine made sure that it was no slouch either.

The 12-cylinder made 370hp and 266lb-ft (361Nm) of torque. However, initial prototypes and show cars used a 5.0-liter V12. And this gave Walter Wolf, who was the Canadian F1 team owner at the time, an idea to increase the performance of his personal Countach.

Also Watch: The Lamborghini Countach Is Still Hilariously Absurd To Drive

Thus, he asked for the help of Lambo’s engineer, Gianpaolo Dallara, who installed a 5.0-liter engine and larger Pirelli tires. The latter were fitted after some bodywork and suspension geometry upgrades.

Impressed by his modified ride, Wolf eventually convinced the automaker to sell the Countach with these extras, and so the LP400 S was born, although without the larger engine. A 4.8-liter V12 was eventually introduced in 1982, in the LP500 S.

RMSothebys has an LP400 S Series II model listed at the upcoming, Monterey, CA auction, on August 24-25. It’s one of only 105 produced, and was fully restored over the course of several years, a process during which more than $250,000 were invested in it.

The auction house states that this Countach, which sports Valentino Balboni’s signature, has less than 35,000km (21,748mi) on the clock, and is described as being “an exceptional example to round off any serious collection”.