17 inch by 9.5 ZO6s in a 93 Z needs to be what offset? Thanks

 

For a 9.5" wide wheel, offsets of 45mm to 56mm will work. 45mm puts the tire comfortably near the outer edge of the fender, 56mm moves it in about 1/2". No rubbing at stock ride height with a 275/40-17 on the front or a 285/40-17 on the back.

The data I have shows the stock 17x9.5 Z06 as 54mm offset.