This is what 4x 18x10.5" C6 wheels look like w/ 315/30-18 on all corners.

[topdj-com]

I ended up with these Snetterton TSW 18 x 9.5 with nitto 555 275/35/18
I post pic on the other ls1 site. remember I mentioned rotors, when I took the original wheels off and looked. I noticed the rotors have never been removed, the star locks on the studs were still on the rotors all 4 wheels. we pulled the rotors and checked the run out, heck the damn things were perfect.
looks like the original owner had just put fresh pads on before I bought it in June 08. the tires date code was the year the car was sold 2001.
I'm thinking the old fart never drove this car hard at all. its a ws6 convert in NBM not a ding or paint chip on it. No mods under the hood.

[Kaotic_ws6]

purdy nice....sure am glad i got those rims!! the only other ones i like are $3500, i forget wat they are called.

yea they are prolly i forged wheels and they are EXPENSIVE. the set on my car with tires is 6500+.. luckily they were already on there cuz NO WAY i would pay that for some rims.