I've got a set of 235/45-17 Dunlop Graspic DS2's that I used for winter driving with my 2002 Z28. I sold the car and I sold the wheels. That just leaves the tires. Two of them were only used on the front of the car and are probably 70% or better tread (they might be more like 85%, but I won't swear to that without measuring) and two are probably around 50% (rears). They will easily go another winter with the rears on the rear, or if you rotate them, you'll probably get 2 or 3 more seasons out of them. These were mounted on 17x9 10 spoke SS wheels and a 17x9 is the widest tire they are rated to fit on. However, I never got stuck and they worked great (even in 4" of slush and ice). I was using 17" snow tires to clear my 13" brakes, I had 16's for the car until I upgraded brakes, then I used these. I paid about $135 per tire for them new.
$175 obo (local pickup preferred, shipping extra).