The availability of good tires for are cars looks to be a permanent on going problem.The C6 ZO6 rims fit our cars but the rear wheels need 16mm spacers. Racing (hardened) studs should be used also. The spacers are available from
http://www.wheeladapter.com/wheel_spacers.php at reasonable cost.
*Thanks go's out to Dom for the info.
With switching over to the C6 ZO6 18/19 wheel combo for the ZR1 now opens up much more MODERN TIRE TECHNOLOGY that our cars so desperately need.
I had the Goodyear F1 S/C tire on the 93 which at the time the tires were put on the car was the cat's meow. The same tires were offered at that time on the new C6's. After a few thousand miles the F1's grip and ride horribly and are noisey as hell. Those tires along with the GSD3 have since been compared to antiques. With the new Nitto and Michilin's etc. that are available in the C6 sizes makes the rim change a very worth while mod for me.Think safety first.
Another benefit of switching over to the C6 rims is we would now be able to easily switch over to the C6ZO6 brakes that are becoming plentiful and relatively inexpensive for upgraded brakes.
++++Sorry for duplicating Scott , internet timing is everything++++