917 tidbits
 

Since the masses are clustered at the rear of the car and rise vertically towards the rear, Porsche inclined the roll center along the axis of the 917 to correlate with Mass Centroid line above - p. 57

Campbell, Colin. 1973. DESIGN OF RACING SPORTS CARS. Robert Bentley, Cambridge, MA.


http://forums.pelicanparts.com/uploa...1162758888.jpg

Actually that's pretty standard with mid-engined formula cars and prototypes. The front roll center is usually a few centimeters above the surface of the road, while the rear roll center higher. This allows the designer to use sway-bars of reasonable thicknesses.

Yes, I wonder how common it was in 1973? I think Enzo was still trying to keep the cart before the horse, or had just recently abandoned that idea...