Hey its a old thread, but I have just been dealing with the reaccuring starter issue on my '94 Z28 and I seem to have found the problem. The starter for 1993 and 1994 are a 9 tooth drive. The starter for 1995-1997 are a 11 tooth drive. The 11 tooth drive has a thinner mounting flang than the 9 tooth so your problem is you have the 11 tooth starter and the 9 tooth bolts. In my case my car is a late model '94 and when I got a new starter from Napa they sold me the 9 tooth. Since then I have broken one flex plate and 5 starters. Now hopefully putting the 11 tooth in mine for a '95 will solve the problem.