I've had 335's(Michelin Pilot Sports PS2) on the back since I purchased my ZR-1 3 years ago. Good wear, good traction and low noise level. I have 275's up front - tires are mounted on Fikse Profil5 (10X17 front and 11.5X17 rear) - no problems with clearance, espically the back.
I have experminted on track days and found that starting with 25lbs works best - brings tires up to normal pressure (32-35) - this gives me the best handling. I tried lower pressure, but felt like driving on butter!
Source for me has been the Tire Rack - 275's = $285
the 335's = $457.
Just looked at the rear tires and for some strange reason they have have the tread left, compared to the fronts (mounted 3/09). My dod's 64 Sports Fury (383) had the same problem when I was 17
