I spoke to the importer of ROH wheels from Oz. He told me to put my Z28 rims on the GTO and not to worry. They were 16" with snows, I sold them and got 17" BMW rims with snows for an additional $100. The hub on the BMW wheels is a bit bigger than the GM hub, so my rims are held on by lugs alone.Rob said:4th gen F-Body wheels fit fine. The bolt pattern is .65mm difference. SLP races with Firebird wheels. Many have used them for everyday wheels also. I've seen pictures of WS6 wheels and they fit fine.
How thick is a human hair? The diiference of .325mm from lug to lug is probably the thickness of the paint on the wheels.