I agreed to help a site out with upgrading from ubb.classic to ubb.threads. I don't know ubb.classic at all and I'm not too familiar with ubb.threads. where does ubb.classic store its database config file so I can run a database backup so do some testing on the ubb.classic to ubb.threads importer script.
FYI. It is suggested to update classic to a newer version. prior to upgrading to ubbthreads.. Classic 6-7-3 is in the members area. usually as long as classic is in the 6.X series it will work to upgrade to threads. If your classic is in the 5.X series then you will nee to update it.