Going from 17's to 18's, what to keep in mind....

[trapin]

I have a few questions. The wheels I have on my car now were ordered a few years before I switched to the ATS spindles and Touring Classics brake system. As I've come to find out as recently as yesterday my current wheels will no longer work because I don't have the minimum 1" of caliper clearance for the C5 caliper. Wheel spacers are not an option. So now I have to sell them and I figure if I'm going to make a wheel change I might as well step up to an 18" wheel since I think they look better on a '67-'68 Camaro. What I need to know is....what size and backspacing will work? For reference the wheels that are on there right now are...

Front - 17X8 (4.75 BS)
Rear - 17X9.5 (5.5 BS)

If I step up to an 18 would I just keep the same backspacing or would it need to be adjusted some in the front? I'm guessing turning radius would be reduced with the larger wheel. Also...If I tell them I need that 1" caliper clearance would that alter the back spacing as well?

Thanks for any help you can give.

[Chad-1stGen]

Only ting I can speak to based on some of my own research into the ATS spindle/vette brakes/rims is that the caliper clearance will only effect backspacing if you need to use spacers which will depend on the rim design.