if you flsahed a downloaded bios from the internet , im sure you checked the bios version number before you flashed your cards ...and saved each original bios file for each card separately ...
The same VGA card from the same manufacturer with the same model number can have many different bios version !!!
Rom files are not interchangeable . You can flash them to another card with the same model number , but then your hashrate will drop to lower 20's or under or just going up and down , or working for a few days and then stop hashing ,  and you have a chance you  might going to destroy your card
My suggestion would be , flash back the original saved bios , reset all overclocking settings and try your cards with default settings ... then fine tune your cards slowly , step by step ..

Higher ASIC quality cards have more overclocking potential ...