Still a strong vintage-racing participant, chassis NO. 0222 is shown competitng during the 2010 Le Mans Classic. (Photo: Wouter Melissen)

In Hugus' hands, the A3/C made its racing debut early in 1964. It proved quite competitive until it was thrown down the leader board with transmission problems. The gearbox had to be swapped twice, and the car eventually finished in a lowly 39th position.

Back in Europe, the first A3/C also showed great potential and clocked the 10th fastest time during the Le Mans trials. A new car was readied for the Le Mans race and it was on its way to a very commendable finish when a poorly installed fresh brake pad ripped the rotor to pieces. Two hours were lost and the Grifo could do no better than 14th.

It was the start of a pretty successful racing career, however, highlighted by a class win in the 1965 edition of the 24 Hours of Le Mans. The press was understandably impressed by the racing successes and even more so by the performance of the road-going A3/Cs, which still packed a 365-horsepower punch. The car’s road-holding edge especially received universal acclaim.

The Iso Grifo's road-holding qualities are still impressive. (Photo: Wouter Melissen)

In the summer of 1965, the relationship between Rivolta and Bizzarrini quickly deteriorated. The Iso owner wanted Bizzarrini to put his successful A3/C Stradale into series production, but Bizzarrini was far more interested in continuously improving the car. The two ideas conflicted and eventually all ties were severed.

Bizzarrini was now fully independent, and while Iso continued to deliver parts, he was not allowed to use the Grifo name. From then on, after about two dozen Grifo A3/Cs were built, though the cars were marketed as the Bizzarrini 5300 GT. The racing cars received the Corsa monniker and the road cars were badged Strada. Not much later, the Strada was joined by the America model, which sported a fiberglass body and a double -wishbone rear suspension.

Production of the 5300 GT lasted until well into 1968 and a combined total of 115 examples were produced. In those years, Bizzarrini built three 5300 GTs with Targa bodies and a small run of the 1900 GT Europa with smaller engines. The company's racing efforts were focused on the mid-engined P538 from 1966 onwards.

There was no replacement for the 5300 GT and in 1972, Bizzarrini was forced to close his factory. He returned to his consulting activities and has since produced only a number of one-off prototypes.

For a gallery of photos, see Iso Grifo 23/C.

Read more stories like this at: The Ultimate Car Page.