904 no speedo in housing

Hi, I bought a fully rollerized 904 with rev. man valve body, when I got the trans I noticed it does not have a hole in the tailshaft housing for a speedo,and looks like the housing has extra webing by the trans mount,
the spot where it would normally be is cast shut. Is this a newer housing?
What housings came with no hole? I didn't take it apart yet ,can I just replace the tailshaft housing with a different one?

Thank's