Driven by Jim Clark, who qualified on pole, and Dan Gurney, tyre failure led to Clark retiring and Gurney being withdrawn.

It differed principally in featuring a four-cam 4195 cc (255ci) DOHC Ford V8 with Hilborn fuel injection, producing 425 bhp (317 kW), through a ZF 2DS20 gearbox.

[2] The Dunlop tyres failed during the race, leading to Clark crashing and Dan Gurney being withdrawn, much to Ford's displeasure.

[3] Later that year Parnelli Jones won twice in a Lotus 43 at Milwaukee and Trenton.

Foyt won three USAC races in a Lotus 34 on his way to second in that years championship, while Parnelli Jones finished second at Indianapolis behind Jim Clark's Lotus 38.