I would also include the Chaparral 2k.
I would substitute the 1963 Lotus for the 65 race winner. The 63 car was the design that caused everyone else to convert to rear engined chassis.
Frank Lockhart and his Miller of course. But what about the Duesenbergs and other Millers ?
I like the choice of the Penske Ilmor but the innovator was Buick- for several years Buick produced turbo pushrod V-6 engines that were the fastest cars on the track. They were unreliable, but caused everyone to think about the possibilities of a pushrod engine.
The 72 Eagle is a good choice. But what about the 71 McLaren M16 ? It obliterated every track record and introduced modern aerodynamics to Indy.
1976-1977 Parnelli and Penske use of the Cosworth DFX. Within a few years all Indy runners would be powered by this engine.
Best,
Ross