I was listening to Scooter Patrick talk about those cars yesterday. In his words: the easiest car to drive I ever got into. I could just toss it around and steer with the throttle, very forgiving car. Incredibly balanced and engineered.
He ran a McClaren in can am in the early 70s. he was telling me about the 917s and Mark Donahue. He said Mark was the craziest, most out of control driver out there. No one could touch the 917s unless it was raining, then the chaparrals would take over.
Scooter did pretty good in can Am in 74 before they killed the org.
I also hung out with his co-driver, Davey Jordan. Great stories, he really liked Vasek Polak. Here's a very interesting read, kind of a sports car histroy lesson:
http://www.vpracing.com/The_Drivers/Davey_Jordan/davey_jordan.html