I have been told that vette 17 and 18 wheels 9.5 wide and 10.5 will fit on my 89 IROC...can anyone verify this??? Thanks Wizard

 

Most Corvette wheels have huge backspacing. The 18x10.5 C5 Z06 wheels are 8" backspace. The C6 Z06 wheels are even more than that. They require spacers on 4th Gens. With the 3rd Gen rear axle assembly being 3" to 4" narrower than the 4th Gen axles, you will need substantial adapters (2" or more) to make them fit. These are the adapters that bolt to your hubs using the stock studs, then provide a new set of studs for the wheels to bolt to. The 3rd and 4th Gen F-Bodys and the C4/C5/C6 all have the same 4.75" bolt circle. Its the offset/backspace that creates the problems.

Skulte Performance used to sell the adapters, but have dropped out of business. They still have the "how to measure" section on their website, so its good info for 3rd Gen fitments:

http://www.skulte.com/adapterfaq.html

 

Like the posting above said. You are going to have problems. With the spacers or adapters, they are going to set way out from your fender. If that no problem for you then go for it. Now you will not be able to have anyone in the backseat. Because it will rub bad. I have a 4th. Gen. 18x10 with 275/40/18 in the back. from a 2003 vette. Had to put in a 1/2 spacer. Sets out about a little over a half a inch. If I am by myself no problem. But put someone else in the car, if I bend a corner to fast. I will get a little rub. I plan to beat the inside fender a little, and hope that will stop that. And last watch your tire size you dont want to go to small of a sidewall.

 

Why would a properly sized spacer cause the wheels to "set way out from your fender"?