This's one of the 917s used in the Steve McQueen movie
Le Mans. It appeared at the HMRC Vintage races at Mission this past June, where the Porsche USA test driver was unable to get it out of 3rd gear due to the car still being geared for Le Mans' Mulsanne straight.

If you've never had the opportunity to hear one of these, this is it trying to come to grips with Mission's tight road course:
movie (10MB Windows Media file) TURN YOUR SPEAKERS UP!