HELP- How can I tell if 727 is SB or BB?

This is real easy without having to get out the tape measures and slide rules. The 904 has two small bolt holes on the bottom that hold the converter cover on. The 727 has four. The 904 has a four o'clock starter position with a scallop curve at the bottom and the 727 has a three o'clock starter position with no scallop. Easy peasy.