i'd say you have the wrong box....i'm not sure if you could somehow use back you old housing to make it work, but that would need someone with detailed knowledge to undertake in any event if it was even possible (gearbox specialist)....let's see if any of the other members have any experience in this area
ideally you need a ep82 c52 or ep91 c56 gearbox...is your car a turbo or n/a?...as they are differences in these 4 boxes (this is the easiest option)
as a 2nd option, the c52/c56 from the AExxx series could be modified to fit, but again that is work that you may not want to undertake---swapping bell housing, drilling and tapping mount bracket holes, etc