I don't know the correct ones myself, but there are a few different 68060.library files for different manufacturers of accelerator. Make sure the ones you got are definitely for phase 5 / DCE cards... Also, there should also be a dummy 68040.library which replaces the existing 68040.library. If you don't have that in place you're also asking for trouble.
Did you read all the docs included with the 68060.library? It might have come with a file called something like 68040-dummy.library which needs renaming, not simply copying to LIBS:...