the cracks are from the casting...and are normal.
the integra transmissions are s80's...whether its from a jdm itr, itr, gsr, jdm gsr or ls/gs/rs.
to really find out which transmission you have youll need to count the number of teeth of the final drive, which means taking it apart.
otherwise, putting it in and driving around will allow you to quickly realize which transmission you have.