my question is what kind of spacer will i need and/or how much offset is on my stock aluminum wheels so i can use these wheels i have seen a few pics on the internet of 81's with ZO6 rims and one with 22" craigers which looked awesome but i think id rather have the 05 or 06 ZO6 wheels has anyone done this? thanks

 

You can measure the offset on your wheels. It is the distance between the center of the rim width of the wheel and the inside mounting surface face. The original rally wheels were close to zero offset.

Here's a website that you can search for "wheel offset": http://topbuzz.co.uk/

Also here's the pic you'll get. Backspacing is the distance from the inside rim width to the mounting surface.

[IMG]local://upfiles/1957/5B6BC6FC6C474C89BE0EEBFCF88EE6CC.gif[/IMG]