i had a 1.8 in my e30 now i have a 2.5 from a 90. I bought a center bearing for the 90. the holes are not wide enough accross to mount correctly. the driveshaft is from a 88 325is. i was told when i bought it that the center bearings were the same. i cant use the 1.8 one since it is shot.I dont want to buy one from a 318i since it may be too small.
The centre bearing design changed at some point in the e30 lifecycle - I think around 87 or 88. There's a late style and early style one with different mounting points. Sounds like you have the late style and that you need the early style.