Right now I have stock rims on my 02 z28 and think I have found the ones I want but not sure on fitment. I have been looking at a 18x8.5 with a 56mm offset front and a 19x10 with a 79mm offset rear. It says I need a 1.25 inch spacer for them to fit. But if I go to 19x11 with a 64mm offset it says nothing about needing spacers. I really like the rims but do not want to use a spacer. Can anyone give me more insight on these wheels cause I still need to get tires on it too.

 

11.0" wide wheels need a 50mm offset (almost an 8" backspace) to keep the outside edge of the tire just under the edge of the fender, and not hitting the bump stop or inner fender. Usually still requires hammering the inner fenders and cutting the projecting edge off the bump stop bracket.

The 11.0" 64mm wheels have ~8.5" backspace. You would need 64mm - 50mm = 14mm = 0.55", or roughly a 9/16" spacer.

What I have found over the years is that there is a huge variation in the rear fender wells on the 4th Gens. You might get very lucky and be able to run the 64mm offset wheels without the spacers, but it's going to be hit or miss.

On the 19x10.0" 79mm offset wheels, you could get by with 0.50 - 0.75" spacers, but the wheel would be sort of deep in the wheel well. Thats why the individual who posted the "sticky" on the C6 wheels on a 4th Gen, on this forum used the 1.25" spacers - to push the wheel out toward the edge of the fender.