When my son was autocrossing his '67 Barracuda we encountered this problem. The car was initially built retaining small bolt pattern and Kelsey-Hayes discs up front. When we started running Nascar slicks we had to make up some 15x10 small bolt rims. After a few events he was out on a run when we heard a rotational grinding/clicking. One center had cracked, but not at a lug.

At that point in time we swapped to big bolt and picked up two Pete Paulsen circle track 15x10s with custom offset. We took two of the small bolt wheels and swapped centers with some 14" rallye centers. Never had another wheel problem. We still have the Paulsen rims, but sold the others.