I have a 49 GMC pick up with 6 lug GM Rally Wheels with a ZC code. They were with the truck when I bought it as a stalled project. I think they mabe from a 80's Blazer, but not sure. I'm getting a bit of wheel rub on the outer edge of the fender when I hit a bump. I need to replace the wheels with a different offset. I don't know what to look for as I don't have and can't find a code chart that lists the ZC code so I can determine what I have.

Does anyone have a chart or can you direct me to one. I've contacted a local tire shop but they haven't replied yet. I'd like to determine what the ZC code represents as well as determine what code to look for as the replacement.

If interested there are pictures of the truck (as well as my other 2 projects) on my Facepage Tom Strojinc.