upgrade to 8.4 with new character set

To those that know,

We originally built our database with a character set of SQL_ASCII.  We now know the error of our foolish ways.  We are trying to upgrade to 8.4 and the windows binaries would like us to use UTF8.  I would like to use a backup to restore onto the new installation, however I am getting warnings and errors about how I am trying to restore a SQL_ASCII character set to a UTF8 Database.  I need to have confidence that my data is intact before I can continue with the upgrade.  I was wondering what would be the best course of action.  I currently have the 8.4 database installed on a separate machine for testing. 

Thank you for all your help

Jonathan Schindler